Refactoring, rename isNil to isNull.

git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@1428206 13f79535-47bb-0310-9956-ffa450edef68

104 files changed, 905 insertions, 905 deletions

diff --git a/sca-cpp/trunk/components/cache/datacache.cpp b/sca-cpp/trunk/components/cache/datacache.cpp
index 4fafd9e345..b96fe92b71 100644
--- a/sca-cpp/trunk/components/cache/datacache.cpp
+++ b/sca-cpp/trunk/components/cache/datacache.cpp
@@ -48,12 +48,12 @@ const failable<value> get(const value& key, const lvvlambda& rcache1, const lvvl
 
     // Lookup level1 cache
     const value val1 = rcache1(mklist<value>("get", key));
-    if (!isNil(val1))
+    if (!isNull(val1))
         return val1;
 
     // Lookup level2 cache
     const value val2 = rcache2(mklist<value>("get", key));
-    if (isNil(val2)) {
+    if (isNull(val2)) {
         ostringstream os;
         os << "Couldn't get cache entry: " << key;
         return mkfailure<value>(str(os), 404, false);
diff --git a/sca-cpp/trunk/components/cache/memcache.cpp b/sca-cpp/trunk/components/cache/memcache.cpp
index e1a3c7e9af..a15250c37b 100644
--- a/sca-cpp/trunk/components/cache/memcache.cpp
+++ b/sca-cpp/trunk/components/cache/memcache.cpp
@@ -68,7 +68,7 @@ const failable<value> put(const list<value>& params, const memcache::MemCached&
 const failable<value> patch(const list<value>& params, const memcache::MemCached& ch) {
     // Read patch
     value p = assoc<value>("patch", assoc<value>("content", car<value>(cadr(params))));
-    if (isNil(p))
+    if (isNull(p))
         return mkfailure<value>("Couldn't read patch script");
     const string script = cadr<value>(p);
     debug(script, "memcache::patch::script");
@@ -82,7 +82,7 @@ const failable<value> patch(const list<value>& params, const memcache::MemCached
     // Apply patch
     scheme::Env env = scheme::setupEnvironment();
     const value pval = scheme::evalScript(cons<value>("patch", scheme::quotedParameters(mklist<value>(car(params), hasContent(ival)? content(ival) : (value)list<value>()))), is, env);
-    if (isNil(pval)) {
+    if (isNull(pval)) {
         ostringstream os;
         os << "Couldn't patch memcached entry: " << car(params);
         return mkfailure<value>(str(os), 404, false);
@@ -109,7 +109,7 @@ const failable<value> del(const list<value>& params, const memcache::MemCached&
  * Convert a list of properties to a list of server addresses.
  */
 const list<string> servers(const list<value>& params) {
-    if (isNil(params))
+    if (isNull(params))
         return list<string>();
     const value s = ((lvvlambda)car(params))(nilListValue);
     return cons<string>(s, servers(cdr(params)));
diff --git a/sca-cpp/trunk/components/cache/memcache.hpp b/sca-cpp/trunk/components/cache/memcache.hpp
index 7962d1caa0..06e2061a09 100644
--- a/sca-cpp/trunk/components/cache/memcache.hpp
+++ b/sca-cpp/trunk/components/cache/memcache.hpp
@@ -95,10 +95,10 @@ private:
     }
 
     const failable<bool> addServers(apr_memcache_t* const m, const list<string>& servers) {
-        if (isNil(servers))
+        if (isNull(servers))
             return true;
         const list<string> toks = tokenize(":", car(servers));
-        const failable<bool> r = addServer(m, car(toks), isNil(cdr(toks))? 11211 : atoi(c_str(cadr(toks))));
+        const failable<bool> r = addServer(m, car(toks), isNull(cdr(toks))? 11211 : atoi(c_str(cadr(toks))));
         if (!hasContent(r))
             return r;
         return addServers(m, cdr(servers));
diff --git a/sca-cpp/trunk/components/cache/memocache.cpp b/sca-cpp/trunk/components/cache/memocache.cpp
index 5539ccee2f..6ac3cece26 100644
--- a/sca-cpp/trunk/components/cache/memocache.cpp
+++ b/sca-cpp/trunk/components/cache/memocache.cpp
@@ -47,7 +47,7 @@ const failable<value> memoize(const list<value>& params, const lvvlambda& relay,
 
     // Lookup memoized value from cache
     const value val = cache(mklist<value>("get", params));
-    if (!isNil(val)) {
+    if (!isNull(val)) {
         debug(val, "memocache::memoize::cached");
         return val;
     }
diff --git a/sca-cpp/trunk/components/cache/partitioner.cpp b/sca-cpp/trunk/components/cache/partitioner.cpp
index 8a56a7f932..c7c49c04de 100644
--- a/sca-cpp/trunk/components/cache/partitioner.cpp
+++ b/sca-cpp/trunk/components/cache/partitioner.cpp
@@ -44,7 +44,7 @@ const failable<list<value> > partition(const value& key, const lvvlambda& select
 
     // Call the selector component to convert the given key to a list of partitions
     const value p = selector(mklist<value>("get", key, partitions));
-    if (isNil(p)) {
+    if (isNull(p)) {
         ostringstream os;
         os << "Couldn't get partition: " << key;
         return mkfailure<list<value> >(str(os), -1, false);
@@ -57,12 +57,12 @@ const failable<list<value> > partition(const value& key, const lvvlambda& select
  * Get lists of items from a list of partitions.
  */
 const failable<list<value> > getlist(const value& key, const list<value>& partitions) {
-    if (isNil(partitions))
+    if (isNull(partitions))
         return nilListValue;
 
     const lvvlambda l = car(partitions);
     const value val = l(mklist<value>("get", key));
-    if (isNil(val))
+    if (isNull(val))
         return getlist(key, cdr(partitions));
     if (!isList(val)) {
         ostringstream os;
@@ -92,7 +92,7 @@ const failable<value> get(const value& key, const lvvlambda& selector, const lis
     if (length(p) == 1) {
         const lvvlambda l = car(p);
         const value val = l(mklist<value>("get", key));
-        if (isNil(val)) {
+        if (isNull(val)) {
             ostringstream os;
             os << "Couldn't get entry from partition: " << key;
             return mkfailure<value>(str(os), 404, false);
diff --git a/sca-cpp/trunk/components/chat/chat-sendreceiver.cpp b/sca-cpp/trunk/components/chat/chat-sendreceiver.cpp
index 94577b7551..7669f91f36 100644
--- a/sca-cpp/trunk/components/chat/chat-sendreceiver.cpp
+++ b/sca-cpp/trunk/components/chat/chat-sendreceiver.cpp
@@ -55,7 +55,7 @@ const failable<value> post(const list<value>& params, XMPPClient& xc) {
  */
 const failable<value> start(const list<value>& params) {
     // Extract the relay reference and the XMPP JID and password
-    const bool hasRelay = !isNil(cddr(params));
+    const bool hasRelay = !isNull(cddr(params));
     const lvvlambda rel = hasRelay? (lvvlambda)car(params) : lvvlambda();
     const list<value> props = hasRelay? cdr(params) : params;
     const value jid = ((lvvlambda)car(props))(nilListValue);
@@ -71,7 +71,7 @@ const failable<value> start(const list<value>& params) {
     worker w(3);
     const lambda<const failable<bool>(const value&, const value&, XMPPClient&)> rl = [rel](const value& jid, const value& val, unused XMPPClient& xc) -> const failable<bool> {
         // A relay function that posts the XMPP messages it receives to a relay component reference.
-        if (isNil(rel))
+        if (isNull(rel))
             return true;
         debug(jid, "chat::relay::jid");
         debug(val, "chat::relay::value");
diff --git a/sca-cpp/trunk/components/chat/xmpp.hpp b/sca-cpp/trunk/components/chat/xmpp.hpp
index 31b4ed3a13..945f1cadc1 100644
--- a/sca-cpp/trunk/components/chat/xmpp.hpp
+++ b/sca-cpp/trunk/components/chat/xmpp.hpp
@@ -176,7 +176,7 @@ int messageHandler(unused xmpp_conn_t* const conn, xmpp_stanza_t* const stanza,
     XMPPClient& xc = *(XMPPClient*)udata;
     const char* const from = xmpp_stanza_get_attribute(stanza, "from");
     const char* const text = xmpp_stanza_get_text(xmpp_stanza_get_child_by_name(stanza, "body"));
-    if (isNil((lambda<const failable<bool>(const value&, const value&, XMPPClient&)>)xc.listener))
+    if (isNull((lambda<const failable<bool>(const value&, const value&, XMPPClient&)>)xc.listener))
         return 1;
     const value val(content(scheme::readValue(text)));
     debug(from, "chat::messageHandler::from");
@@ -315,7 +315,7 @@ const failable<bool> listen(const lambda<const failable<bool>(const value&, cons
     xc.listener = listener;
     xmpp_handler_add(xc.conn, messageHandler, NULL, "message", NULL, &xc);
     xc.ctx->loop_status = XMPP_LOOP_RUNNING;
-    while(xc.connected && !isNil((lambda<const failable<bool>(const value&, const value&, XMPPClient&)>)xc.listener) && xc.ctx->loop_status == XMPP_LOOP_RUNNING)
+    while(xc.connected && !isNull((lambda<const failable<bool>(const value&, const value&, XMPPClient&)>)xc.listener) && xc.ctx->loop_status == XMPP_LOOP_RUNNING)
         xmpp_run_once(xc.ctx, 1000L);
     return true;
 }
diff --git a/sca-cpp/trunk/components/constdb/constdb.cpp b/sca-cpp/trunk/components/constdb/constdb.cpp
index 2d34ed2b73..d5d2d05e3a 100644
--- a/sca-cpp/trunk/components/constdb/constdb.cpp
+++ b/sca-cpp/trunk/components/constdb/constdb.cpp
@@ -68,7 +68,7 @@ const failable<value> put(const list<value>& params, const tinycdb::TinyCDB& cdb
 const failable<value> patch(const list<value>& params, const tinycdb::TinyCDB& cdb) {
     // Read patch
     value p = assoc<value>("patch", assoc<value>("content", car<value>(cadr(params))));
-    if (isNil(p))
+    if (isNull(p))
         return mkfailure<value>("Couldn't read patch script");
     const string script = cadr<value>(p);
     debug(script, "tinycdb::patch::script");
@@ -82,7 +82,7 @@ const failable<value> patch(const list<value>& params, const tinycdb::TinyCDB& c
     // Apply patch
     scheme::Env env = scheme::setupEnvironment();
     const value pval = scheme::evalScript(cons<value>("patch", scheme::quotedParameters(mklist<value>(car(params), hasContent(ival)? content(ival) : (value)list<value>()))), is, env);
-    if (isNil(pval)) {
+    if (isNull(pval)) {
         ostringstream os;
         os << "Couldn't patch tinycdb entry: " << car(params);
         return mkfailure<value>(str(os), 404, false);
diff --git a/sca-cpp/trunk/components/filedb/filedb.cpp b/sca-cpp/trunk/components/filedb/filedb.cpp
index b28cc9bedb..efc5838fa6 100644
--- a/sca-cpp/trunk/components/filedb/filedb.cpp
+++ b/sca-cpp/trunk/components/filedb/filedb.cpp
@@ -68,7 +68,7 @@ const failable<value> put(const list<value>& params, const filedb::FileDB& db) {
 const failable<value> patch(const list<value>& params, const filedb::FileDB& db) {
     // Read patch
     value p = assoc<value>("patch", assoc<value>("content", car<value>(cadr(params))));
-    if (isNil(p))
+    if (isNull(p))
         return mkfailure<value>("Couldn't read patch script");
     const string script = cadr<value>(p);
     debug(script, "filedb::patch::script");
@@ -82,7 +82,7 @@ const failable<value> patch(const list<value>& params, const filedb::FileDB& db)
     // Apply patch
     scheme::Env env = scheme::setupEnvironment();
     const value pval = scheme::evalScript(cons<value>("patch", scheme::quotedParameters(mklist<value>(car(params), hasContent(ival)? content(ival) : (value)list<value>()))), is, env);
-    if (isNil(pval)) {
+    if (isNull(pval)) {
         ostringstream os;
         os << "Couldn't patch file database entry: " << car(params);
         return mkfailure<value>(str(os), 404, false);
diff --git a/sca-cpp/trunk/components/filedb/filedb.hpp b/sca-cpp/trunk/components/filedb/filedb.hpp
index 41dde88bef..89e0c1b424 100644
--- a/sca-cpp/trunk/components/filedb/filedb.hpp
+++ b/sca-cpp/trunk/components/filedb/filedb.hpp
@@ -91,7 +91,7 @@ private:
  * Convert a key to a file name.
  */
 const string filename(const list<value>& path, const string& root) {
-    if (isNil(path))
+    if (isNull(path))
         return root;
     const string name = root + "/" + (isString(car(path))? (string)car(path) : write(content(scheme::writeValue(car(path)))));
     return filename(cdr(path), name);
@@ -107,7 +107,7 @@ const string filename(const value& key, const string& root) {
  * Make the parent directories of a keyed file.
  */
 const failable<bool> mkdirs(const list<value>& path, const string& root) {
-    if (isNil(cdr(path)))
+    if (isNull(cdr(path)))
         return true;
     const string dir = root + "/" + (isString(car(path))? (string)car(path) : write(content(scheme::writeValue(car(path)))));
     mkdir(c_str(dir), S_IRWXU);
diff --git a/sca-cpp/trunk/components/sqldb/pgsql.hpp b/sca-cpp/trunk/components/sqldb/pgsql.hpp
index 5e0004c4e6..e7c7c5d5cd 100644
--- a/sca-cpp/trunk/components/sqldb/pgsql.hpp
+++ b/sca-cpp/trunk/components/sqldb/pgsql.hpp
@@ -320,7 +320,7 @@ const failable<bool> patch(const value& key, const value& val, const PGSql& pgsq
  * Convert a key to an item id.
  */
 const list<value> keyid(const list<value>& key) {
-    if (isNil(key))
+    if (isNull(key))
         return nilListValue;
     if (isList(car(key)))
         return keyid(cdr(key));
@@ -331,7 +331,7 @@ const list<value> keyid(const list<value>& key) {
  * Convert a key to a (param name, value) assoc.
  */
 const list<value> keyparams(const list<value>& key) {
-    if (isNil(key))
+    if (isNull(key))
         return nilListValue;
     if (!isList(car(key)))
         return keyparams(cdr(key));
@@ -386,11 +386,11 @@ const failable<value> get(const value& key, const PGSql& pgsql) {
     const list<value> rank = assoc<value>("rank", kparams);
     const list<value> id = lk? keyid(key) : nilListValue;
     const list<value> atable = assoc<value>("table", kparams);
-    const string table = isNil(atable)? pgsql.table : (string)cadr(atable);
+    const string table = isNull(atable)? pgsql.table : (string)cadr(atable);
     const list<value> akname = assoc<value>("kcolumn", kparams);
-    const string kname = isNil(akname)? pgsql.kname : (string)cadr(akname);
+    const string kname = isNull(akname)? pgsql.kname : (string)cadr(akname);
     const list<value> avname = assoc<value>("vcolumn", kparams);
-    const string vname = isNil(avname)? pgsql.vname : (string)cadr(avname);
+    const string vname = isNull(avname)? pgsql.vname : (string)cadr(avname);
 
     // Build the SQL query
     const char* sqlparams[6];
@@ -398,60 +398,60 @@ const failable<value> get(const value& key, const PGSql& pgsql) {
     int w = 0;
     ostringstream sqlos;
     sqlos << "select data." << kname << ", data." << vname;
-    if (!isNil(textsearch)) {
+    if (!isNull(textsearch)) {
         // Text search, setup text result ranking
         sqlos << ", ts_rank_cd(to_tsvector(data." << vname << "), tsquery, 32) as tsrank";
     }
-    if (!isNil(rank)) {
+    if (!isNull(rank)) {
         // Ranking, setup rank expression
         const string rs = (string)cadr(rank);
         sqlparams[p++] = c_str(rs);
         sqlos << ", $" << p << " as rank";
     }
     sqlos << " from " << table << " data";
-    if (!isNil(textsearch)) {
+    if (!isNull(textsearch)) {
         // Text search, define the query
         const string ts = tstranslate((string)cadr(textsearch));
         sqlparams[p++] = c_str(ts);
         sqlos << ", plainto_tsquery($" << p << ") tsquery";
     }
-    if (!lk || !isNil(id)) {
+    if (!lk || !isNull(id)) {
         // Query of the form key = id
         sqlparams[p++] = c_str(write(content(scheme::writeValue(lk? (value)id : key))));
         sqlos << (w == 0? " where" : " and");
         sqlos << " data." << kname << " = $" << p;
         w++;
     }
-    if (!isNil(regex)) {
+    if (!isNull(regex)) {
         // Query of the form key ~ param
         sqlparams[p++] = c_str((string)cadr(regex));
         sqlos << (w == 0? " where" : " and");
         sqlos << " data." << kname << " ~ $" << p;
         w++;
     }
-    if (!isNil(like)) {
+    if (!isNull(like)) {
         // Query of the form key like param
         sqlparams[p++] = c_str((string)cadr(like));
         sqlos << (w == 0? " where" : " and");
         sqlos << " data." << kname << " like $" << p;
         w++;
     }
-    if (!isNil(textsearch)) {
+    if (!isNull(textsearch)) {
         // Text search, apply the query
         sqlos << (w == 0? " where" : " and");
         sqlos << " tsquery @@ to_tsvector(data." << vname << ")";
         w++;
     }
-    if (!isNil(textsearch) || !isNil(rank)) {
+    if (!isNull(textsearch) || !isNull(rank)) {
         // Result ordering
-        sqlos << " order by" << (isNil(rank)? "" : " rank desc") << ((isNil(rank) || isNil(textsearch))? "" : ",") << (isNil(textsearch)? "" : " tsrank desc");
+        sqlos << " order by" << (isNull(rank)? "" : " rank desc") << ((isNull(rank) || isNull(textsearch))? "" : ",") << (isNull(textsearch)? "" : " tsrank desc");
     }
-    if (!isNil(offset)) {
+    if (!isNull(offset)) {
         // Result pagination offset
         sqlos << " offset " << atoi(c_str((string)cadr(offset)));
     }
     // Result limit count
-    const int l = isNil(limit)? 1 : atoi(c_str((string)cadr(limit)));
+    const int l = isNull(limit)? 1 : atoi(c_str((string)cadr(limit)));
     sqlos << " limit " << l << ";";
     
     // Execute the query
diff --git a/sca-cpp/trunk/components/sqldb/sqldb.cpp b/sca-cpp/trunk/components/sqldb/sqldb.cpp
index 75be2c0624..c0fcd0a2f1 100644
--- a/sca-cpp/trunk/components/sqldb/sqldb.cpp
+++ b/sca-cpp/trunk/components/sqldb/sqldb.cpp
@@ -69,7 +69,7 @@ const failable<value> put(const list<value>& params, const pgsql::PGSql& pg) {
 const failable<value> patch(const list<value>& params, const pgsql::PGSql& pg) {
     // Read patch
     value p = assoc<value>("patch", assoc<value>("content", car<value>(cadr(params))));
-    if (isNil(p))
+    if (isNull(p))
         return mkfailure<value>("Couldn't read patch script");
     const string script = cadr<value>(p);
     debug(script, "pgsql::patch::script");
@@ -92,7 +92,7 @@ const failable<value> patch(const list<value>& params, const pgsql::PGSql& pg) {
         istringstream is(script);
         scheme::Env env = scheme::setupEnvironment();
         const value pval = scheme::evalScript(cons<value>("patch", scheme::quotedParameters(mklist<value>(key, hasContent(ival)? content(ival) : (value)list<value>()))), is, env);
-        if (isNil(pval)) {
+        if (isNull(pval)) {
             ostringstream os;
             os << "Couldn't patch postgresql entry: " << key;
             return mkfailure<value>(str(os), 404, false);
diff --git a/sca-cpp/trunk/hosting/server/accounts.py b/sca-cpp/trunk/hosting/server/accounts.py
index 99655620f1..6aa50c9375 100644
--- a/sca-cpp/trunk/hosting/server/accounts.py
+++ b/sca-cpp/trunk/hosting/server/accounts.py
@@ -28,7 +28,7 @@ def accountid(user):
 def get(id, user, cache):
     debug('accounts.py::get::id', id)
     account = cache.get(accountid(user))
-    if isNil(account):
+    if isNull(account):
         return mkentry(user.get(()), user.get(()), user.get(()), now(), ())
     return account
 
diff --git a/sca-cpp/trunk/hosting/server/apps.py b/sca-cpp/trunk/hosting/server/apps.py
index 5b0c1b8831..20c38cb3c5 100644
--- a/sca-cpp/trunk/hosting/server/apps.py
+++ b/sca-cpp/trunk/hosting/server/apps.py
@@ -34,7 +34,7 @@ def put(id, app, user, cache, dashboard, store, composites, pages, icons):
     if car(id) == eid:
         # Check app author
         eapp = cache.get(appid(id))
-        if (not isNil(eapp)) and (author(eapp) != user.get(())):
+        if (not isNull(eapp)) and (author(eapp) != user.get(())):
             debug('apps.py::put', 'different author', author(eapp))
             return False
 
@@ -45,7 +45,7 @@ def put(id, app, user, cache, dashboard, store, composites, pages, icons):
         dashboard.put(id, appentry)
 
         # Create new page and composite if necessary
-        if isNil(eapp):
+        if isNull(eapp):
             comp = mkentry(car(id), car(id), user.get(()), now(), ())
             composites.put(id, comp)
             page = mkentry(car(id), car(id), user.get(()), now(), ())
@@ -57,13 +57,13 @@ def put(id, app, user, cache, dashboard, store, composites, pages, icons):
 
     # Check app author
     eapp = cache.get(appid(id))
-    if (not isNil(eapp)) and (author(eapp) != user.get(())):
+    if (not isNull(eapp)) and (author(eapp) != user.get(())):
         debug('apps.py::put', 'different author', author(eapp))
         return False
 
     # Get app to clone
     capp = cache.get(appid((eid,)))
-    if isNil(capp):
+    if isNull(capp):
         debug('apps.py::put', 'cloned app not found', (eid,))
         return False
 
@@ -80,12 +80,12 @@ def put(id, app, user, cache, dashboard, store, composites, pages, icons):
 # Get an app from the apps db
 def get(id, user, cache, dashboard, store, composites, pages, icons):
     debug('apps.py::get::id', id)
-    if isNil(id):
+    if isNull(id):
         return (("'feed", ("'title", "Apps"), ("'id", "apps")),)
 
     # Get the requested app
     app = cache.get(appid(id))
-    if isNil(app):
+    if isNull(app):
         debug('apps.py::get', 'app not found', id)
         return None
 
@@ -99,7 +99,7 @@ def delete(id, user, cache, dashboard, store, composites, pages, icons):
 
     # Get the requested app
     app = cache.get(appid(id))
-    if isNil(app):
+    if isNull(app):
         debug('apps.py::delete', 'app not found', id)
         return False
 
diff --git a/sca-cpp/trunk/hosting/server/atomutil.py b/sca-cpp/trunk/hosting/server/atomutil.py
index 8f01f81d3a..2fbcaff8ce 100644
--- a/sca-cpp/trunk/hosting/server/atomutil.py
+++ b/sca-cpp/trunk/hosting/server/atomutil.py
@@ -21,42 +21,42 @@ from time import strftime, gmtime
 
 # Make an ATOM entry
 def mkentry(title, id, author, updated, content):
-    return (("'entry", ("'title", title), ("'id", id), ("'author", author), ("'updated", updated), ("'content",) if isNil(content) else ("'content", content)),)
+    return (("'entry", ("'title", title), ("'id", id), ("'author", author), ("'updated", updated), ("'content",) if isNull(content) else ("'content", content)),)
 
 # Make an ATOM feed
 def mkfeed(title, id, author, updated, entries):
-    return (("'entry", ("'title", title), ("'id", id), ("'author", author), ("'updated", updated), ("'content",) if isNil(content) else ("'content", content)),)
+    return (("'entry", ("'title", title), ("'id", id), ("'author", author), ("'updated", updated), ("'content",) if isNull(content) else ("'content", content)),)
 
 # Return ATOM attributes
 def title(e):
-    if isNil(e):
+    if isNull(e):
         return ()
     t = assoc("'title", car(e))
-    return None if isNil(t) else cadr(t)
+    return None if isNull(t) else cadr(t)
 
 def entryid(e):
-    if isNil(e):
+    if isNull(e):
         return ()
     id = assoc("'id", car(e))
-    return None if isNil(id) else cadr(id)
+    return None if isNull(id) else cadr(id)
 
 def author(e):
-    if isNil(e):
+    if isNull(e):
         return ()
     a = assoc("'author", car(e))
-    return None if isNil(a) else cadr(a)
+    return None if isNull(a) else cadr(a)
 
 def updated(e):
-    if isNil(e):
+    if isNull(e):
         return ()
     u = assoc("'updated", car(e))
-    return None if isNil(u) else cadr(u)
+    return None if isNull(u) else cadr(u)
 
 def content(e):
-    if isNil(e):
+    if isNull(e):
         return ()
     c = assoc("'content", car(e))
-    return () if isNil(c) or isNil(cdr(c)) else c[len(c) - 1]
+    return () if isNull(c) or isNull(cdr(c)) else c[len(c) - 1]
 
 # Return the current time
 def now():
diff --git a/sca-cpp/trunk/hosting/server/authn.py b/sca-cpp/trunk/hosting/server/authn.py
index 02c24a2852..e3d6711cbd 100644
--- a/sca-cpp/trunk/hosting/server/authn.py
+++ b/sca-cpp/trunk/hosting/server/authn.py
@@ -25,7 +25,7 @@ def authnid(id):
 # Get a user's authentication
 def get(id, cache):
     authn = cache.get(authnid(id))
-    if isNil(authn):
+    if isNull(authn):
         return None
     return authn
 
diff --git a/sca-cpp/trunk/hosting/server/client-test.hpp b/sca-cpp/trunk/hosting/server/client-test.hpp
index 9d887e0558..7620326421 100644
--- a/sca-cpp/trunk/hosting/server/client-test.hpp
+++ b/sca-cpp/trunk/hosting/server/client-test.hpp
@@ -221,7 +221,7 @@ const list<future<bool> > startPost(const worker& w, const int threads, const bl
 }
 
 const bool checkPost(const list<future<bool> >& r) {
-    if (isNil(r))
+    if (isNull(r))
         return true;
     assert(car(r) == true);
     return checkPost(cdr(r));
@@ -279,7 +279,7 @@ const list<pid_t> startPost(const int procs, const blambda& l) {
 }
 
 const bool checkPost(const list<pid_t>& r) {
-    if (isNil(r))
+    if (isNull(r))
         return true;
     int status;
     waitpid(car(r), &status, 0);
diff --git a/sca-cpp/trunk/hosting/server/composites.py b/sca-cpp/trunk/hosting/server/composites.py
index 9e4b40b669..d0276ab5ee 100644
--- a/sca-cpp/trunk/hosting/server/composites.py
+++ b/sca-cpp/trunk/hosting/server/composites.py
@@ -31,7 +31,7 @@ def put(id, comp, user, cache, apps):
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('composites.py::put', 'app not found', id)
         return False
 
@@ -48,12 +48,12 @@ def put(id, comp, user, cache, apps):
 # Get a composite from the composite db
 def get(id, user, cache, apps):
     debug('composites.py::get::id', id)
-    if isNil(id):
+    if isNull(id):
         return (("'feed", ("'title", "Composites"), ("'id", "composites")),)
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('composites.py::get', 'app not found', id)
 
         # Return a default new composite
@@ -61,7 +61,7 @@ def get(id, user, cache, apps):
 
     # Get the requested composite
     comp = cache.get(compid(id))
-    if isNil(comp):
+    if isNull(comp):
         debug('composites.py::get', 'composite not found', id)
 
         # Return a default new composite
@@ -78,7 +78,7 @@ def delete(id, user, cache, apps):
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('composites.py::delete', 'app not found', id)
         return False
 
diff --git a/sca-cpp/trunk/hosting/server/dashboards.py b/sca-cpp/trunk/hosting/server/dashboards.py
index a87f1fa819..d2dca67ddd 100644
--- a/sca-cpp/trunk/hosting/server/dashboards.py
+++ b/sca-cpp/trunk/hosting/server/dashboards.py
@@ -28,10 +28,10 @@ def dashboardid(user):
 def getdashboard(id, cache):
     debug('dashboards.py::getdashboard::id', id)
     val = cache.get(id)
-    if isNil(val):
+    if isNull(val):
         return ()
     dashboard = cdddr(car(val))
-    if not isNil(dashboard) and isList(car(cadr(car(dashboard)))):
+    if not isNull(dashboard) and isList(car(cadr(car(dashboard)))):
         # Expand list of entries
         edashboard = tuple(map(lambda e: cons("'entry", e), cadr(car(dashboard))))
         debug('dashboards.py::getdashboard::edashboard', edashboard)
@@ -53,7 +53,7 @@ def put(id, app, user, cache, apps, ratings):
     debug('dashboards.py::put::app', app)
 
     def putapp(id, app, dashboard):
-        if isNil(dashboard):
+        if isNull(dashboard):
             return app
         if car(id) == entryid(dashboard):
             return cons(car(app), cdr(dashboard))
@@ -73,15 +73,15 @@ def mergeapps(entries, apps, ratings):
         debug('store.py::mergeapp::entry', entry)
         id = (entryid(entry),)
         app = apps.get(id)
-        if isNil(app):
+        if isNull(app):
             return ((),)
         info = content(app)
         rating = ratings.get(id)
         rates = content(rating)
-        mergedentry = mkentry(title(app), car(id), author(app), updated(app), ("'info",) + (() if isNil(info) else cdr(info)) + (() if isNil(rates) else cdr(rates)))
+        mergedentry = mkentry(title(app), car(id), author(app), updated(app), ("'info",) + (() if isNull(info) else cdr(info)) + (() if isNull(rates) else cdr(rates)))
         return mergedentry
 
-    mergedentries = tuple(filter(lambda e: not isNil(e), map(lambda e: car(mergeapp((e,))), entries)))
+    mergedentries = tuple(filter(lambda e: not isNull(e), map(lambda e: car(mergeapp((e,))), entries)))
     debug('store.py::mergeapps::mergedentries', mergedentries)
     return mergedentries
 
@@ -90,13 +90,13 @@ def get(id, user, cache, apps, ratings):
     debug('dashboards.py::get::id', id)
 
     def findapp(id, dashboard):
-        if isNil(dashboard):
+        if isNull(dashboard):
             return None
         if car(id) == entryid(dashboard):
             return (car(dashboard),)
         return findapp(id, cdr(dashboard))
 
-    if isNil(id):
+    if isNull(id):
         dashboardapps = mergeapps(getdashboard(dashboardid(user), cache), apps, ratings)
         dashboard = ((("'feed", ("'title", "Your Apps"), ("'id", user.get(()))) + dashboardapps),)
         debug('dashboards.py::get::dashboard', dashboard)
@@ -109,11 +109,11 @@ def get(id, user, cache, apps, ratings):
 # Delete apps from the user's dashboard
 def delete(id, user, cache, apps, ratings):
     debug('dashboards.py::delete::id', id)
-    if isNil(id):
+    if isNull(id):
         return cache.delete(dashboardid(user))
 
     def deleteapp(id, dashboard):
-        if isNil(dashboard):
+        if isNull(dashboard):
             return ()
         if car(id) == entryid(dashboard):
             return cdr(dashboard)
diff --git a/sca-cpp/trunk/hosting/server/htdocs/account/index.html b/sca-cpp/trunk/hosting/server/htdocs/account/index.html
index 47c0ea0e9c..9357a89dd6 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/account/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/account/index.html
@@ -133,29 +133,29 @@ var savedpicxml = '';
         var acct = cadr(assoc("'content", acctentry));
 
         var email = assoc("'email", acct);
-        $('userEmail').value = isNil(email) || isNil(cdr(email))? '' : cadr(email);
+        $('userEmail').value = isNull(email) || isNull(cdr(email))? '' : cadr(email);
 
         var desc = assoc("'description", acct);
-        $('userDescription').innerHTML = isNil(desc) || isNil(cdr(desc))? '' : cadr(desc);
+        $('userDescription').innerHTML = isNull(desc) || isNull(cdr(desc))? '' : cadr(desc);
 
         /* TODO disabled for now
         var cal = assoc("'calendar", acct);
         reduce(function(i, evt) {
                 var sched = assoc("'@schedule", evt);
                 var svc = assoc("'@service", evt);
-                $('sched' + i).value = isNil(sched)? '' : cadr(sched);
-                $('service' + i).value = isNil(svc)? '' : cadr(svc);
+                $('sched' + i).value = isNull(sched)? '' : cadr(sched);
+                $('service' + i).value = isNull(svc)? '' : cadr(svc);
                 return i + 1;
-            }, 1, isNil(cal)? mklist() : cadr(cadr(cal)));
+            }, 1, isNull(cal)? mklist() : cadr(cadr(cal)));
 
         var keys = assoc("'keys", acct);
         reduce(function(i, key) {
                 var kn = assoc("'@name", key);
                 var kv = assoc("'@value", key);
-                $('name' + i).value = isNil(kn)? '' : cadr(kn);
-                $('value' + i).value = isNil(kv)? '' : cadr(kv);
+                $('name' + i).value = isNull(kn)? '' : cadr(kn);
+                $('value' + i).value = isNull(kv)? '' : cadr(kv);
                 return i + 1;
-            }, 1, isNil(keys)? mklist() : cadr(cadr(keys)));
+            }, 1, isNull(keys)? mklist() : cadr(cadr(keys)));
         */
 
         savedacctxml = car(atom.writeATOMEntry(valuesToElements(mklist(acctentry))));
@@ -184,7 +184,7 @@ var savedpicxml = '';
         var content = assoc("'content", picentry);
         var picture = assoc("'picture", content);
         var img = assoc("'image", picture);
-        if (!isNil(img))
+        if (!isNull(img))
             $('userPicture').src = cadr(img);
 
         onlinestatus();
@@ -216,11 +216,11 @@ function refreshpic() {
         var token = assoc("'token", picture);
 
         // Update picture
-        if (isNil(token)) {
+        if (isNull(token)) {
             var entryxml = car(atom.writeATOMEntry(valuesToElements(mklist(picentry))));
             savedpicxml = entryxml;
             var img = assoc("'image", picture);
-            if (!isNil(img))
+            if (!isNull(img))
                 $('userPicture').src = cadr(img);
             $('refreshingPicture').style.display = 'none';
             refreshingpic = false;
@@ -237,7 +237,7 @@ function refreshpic() {
  * Save the user's account.
  */
 function saveacct(entryxml) {
-    if (isNil(username))
+    if (isNull(username))
         return false;
     workingstatus(true);
     showstatus('Saving');
@@ -261,7 +261,7 @@ function saveacct(entryxml) {
  * Save the user's picture.
  */
 function savepic(entryxml) {
-    if (isNil(username))
+    if (isNull(username))
         return false;
     workingstatus(true);
     showstatus('Uploading');
diff --git a/sca-cpp/trunk/hosting/server/htdocs/app/index.html b/sca-cpp/trunk/hosting/server/htdocs/app/index.html
index cd033118a3..9ff3a72b0f 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/app/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/app/index.html
@@ -207,7 +207,7 @@ window.addEventListener('online', function(e) {
  * as a list of ids.
  */
 function namedvalue(l, id) {
-    if (isNil(l))
+    if (isNull(l))
         return null;
     var e = car(l);
 
@@ -215,7 +215,7 @@ function namedvalue(l, id) {
     if (car(id) == elementName(e)) {
 
         // Found element matching the whole id path
-        if (isNil(cdr(id)))
+        if (isNull(cdr(id)))
             return e;
 
         // Search for next id segments in child elements
@@ -267,15 +267,15 @@ function setwidgetvalue(e, dv) {
     }
 
     function vattr(dv) {
-        return (elementHasValue(dv) && !isNil(elementValue(dv)))? mklist(mklist('value', isNil(elementValue(dv))? '' : elementValue(dv))) : mklist();
+        return (elementHasValue(dv) && !isNull(elementValue(dv)))? mklist(mklist('value', isNull(elementValue(dv))? '' : elementValue(dv))) : mklist();
     }
 
     function sattr(dv) {
         var s = namedElementChild("'htstyle", dv);
-        return isNil(s)? mklist() : mklist(mklist('style', elementHasValue(s)? elementValue(s) : elementChildren(s)))
+        return isNull(s)? mklist() : mklist(mklist('style', elementHasValue(s)? elementValue(s) : elementChildren(s)))
     }
 
-    var attrs = append(append(isNil(htattrs)?  mklist() : map(attr, elementChildren(htattrs)), vattr(dv)), sattr(dv));
+    var attrs = append(append(isNull(htattrs)?  mklist() : map(attr, elementChildren(htattrs)), vattr(dv)), sattr(dv));
 
     // Set the attributes of the widget
     function setattrs(vsetter, attrs, ce) {
@@ -312,7 +312,7 @@ function setwidgetvalue(e, dv) {
                 // Define the stylesheet
                 if (s != '') {
                     var esheet = ui.elementByID(contentdiv, 'style_' + e.id);
-                    if (isNil(esheet)) {
+                    if (isNull(esheet)) {
                         var nesheet = document.createElement('style');
                         nesheet.id = 'style_' + e.id;
                         nesheet.type = 'text/css';
@@ -330,7 +330,7 @@ function setwidgetvalue(e, dv) {
                 ce.setAttribute('style', p);
 
                 // Restart current animation if necessary
-                if (!isNil(aname) && ce.style.webkitAnimationName == aname) {
+                if (!isNull(aname) && ce.style.webkitAnimationName == aname) {
                     ce.style.webkitAnimationName = '';
                     ui.async(function restartanimation() {
                         ce.style.webkitAnimationName = aname;
@@ -381,12 +381,12 @@ function setwidgetvalue(e, dv) {
         return setattrs(setselectvalue, attrs, ce);
     }
     if (e.className == 'list') {
-        var dl = ui.datalist(isNil(dv)? mklist() : mklist(dv));
+        var dl = ui.datalist(isNull(dv)? mklist() : mklist(dv));
         e.innerHTML = dl;
         return dl;
     }
     if (e.className == 'table') {
-        var dl = ui.datatable(isNil(dv)? mklist() : mklist(dv));
+        var dl = ui.datatable(isNull(dv)? mklist() : mklist(dv));
         e.innerHTML = dl;
         return dl;
     }
@@ -422,19 +422,19 @@ function setwidgetvalue(e, dv) {
  * Update the app page with the given app data.
  */
 function updatepage(l) {
-    if (isNil(l))
+    if (isNull(l))
         return true;
 
     // Update the widgets values
     function updatewidget(e) {
         var dv = namedvalue(l, map(function(t) { return "'" + t; }, e.id.split('.')));
-        if (dv == null || isNil(dv))
+        if (dv == null || isNull(dv))
             return e;
         setwidgetvalue(e, dv);
         return e;
     }
 
-    map(updatewidget, filter(function(e) { return !isNil(e.id) && e.id.substring(0, 5) != 'page:'; }, nodeList(ui.elementByID(contentdiv, 'page').childNodes)));
+    map(updatewidget, filter(function(e) { return !isNull(e.id) && e.id.substring(0, 5) != 'page:'; }, nodeList(ui.elementByID(contentdiv, 'page').childNodes)));
     return true;
 }
 
@@ -442,7 +442,7 @@ function updatepage(l) {
  * Convert a document to application data.
  */
 function docdata(doc) {
-    if (isNil(doc))
+    if (isNull(doc))
         return null;
 
     if (json.isJSON(mklist(doc)))
@@ -566,7 +566,7 @@ function fixupwidget(e) {
  * Set initial value of a widget.
  */
 function initwidget(e) {
-    if (!isNil(e.id) && e.id.substring(0, 5) != 'page:')
+    if (!isNull(e.id) && e.id.substring(0, 5) != 'page:')
         setwidgetvalue(e, mklist());
     return e;
 }
@@ -575,9 +575,9 @@ function initwidget(e) {
  * Return the component bound to a uri.
  */
 function isbound(uri, comps) {
-    return !isNil(filter(function(comp) {
-        return !isNil(filter(function(svc) {
-            return !isNil(filter(function(b) {
+    return !isNull(filter(function(comp) {
+        return !isNull(filter(function(svc) {
+            return !isNull(filter(function(b) {
                 return uri == scdl.uri(b);
             }, scdl.bindings(svc)));
         }, scdl.services(comp)));
@@ -592,7 +592,7 @@ function getappdata(appname, page, compos) {
 
         // Eval a component init script
         function evalcompinit(doc) {
-            if (isNil(doc))
+            if (isNull(doc))
                 return true;
             var js = car(json.readJSON(mklist(doc)));
             if (!elementHasValue(js))
@@ -609,7 +609,7 @@ function getappdata(appname, page, compos) {
         }
 
         // Setup the widgets
-        map(setupwidget, filter(function(e) { return !isNil(e.id); }, nodeList(ui.elementByID(contentdiv, 'page').childNodes)));
+        map(setupwidget, filter(function(e) { return !isNull(e.id); }, nodeList(ui.elementByID(contentdiv, 'page').childNodes)));
 
         // Get the app components
         var comps = scdl.components(compos);
@@ -617,7 +617,7 @@ function getappdata(appname, page, compos) {
         // Get the component app data
         if (isbound("start", comps)) {
             startcomp.get(location.search, function(doc, e) {
-                if (isNil(doc)) {
+                if (isNull(doc)) {
                     debug('error on get(start, ' + location.search + ')', e);
                     return false;
                 }
@@ -630,7 +630,7 @@ function getappdata(appname, page, compos) {
         // Get and eval the optional timer, animation and location watch setup scripts
         if (isbound("timer", comps)) {
             timercomp.get('setup', function(doc, e) {
-                if (isNil(doc)) {
+                if (isNull(doc)) {
                     debug('error on get(timer, setup)', e);
                     return false;
                 }
@@ -642,7 +642,7 @@ function getappdata(appname, page, compos) {
 
         if (isbound("animation", comps)) {
             animationcomp.get('setup', function(doc, e) {
-                if (isNil(doc)) {
+                if (isNull(doc)) {
                     debug('error on get(animation, setup)', e);
                     return false;
                 }
@@ -654,7 +654,7 @@ function getappdata(appname, page, compos) {
 
         if (isbound("location", comps)) {
             locationcomp.get('setup', function(doc, e) {
-                if (isNil(doc)) {
+                if (isNull(doc)) {
                     debug('error on get(location, setup)', e);
                     return false;
                 }
@@ -677,7 +677,7 @@ function getappdata(appname, page, compos) {
  */
 function atompage(doc) {
     var entry = atom.readATOMEntry(mklist(doc));
-    if (isNil(entry))
+    if (isNull(entry))
         return mklist();
     var content = namedElementChild("'content", car(entry));
     if (content == null)
@@ -691,7 +691,7 @@ function atompage(doc) {
 function getapppage(appname, compos) {
     pagecomp.get(appname, function(doc, e) {
         //debug('page get');
-        if (isNil(doc)) {
+        if (isNull(doc)) {
             debug('error in getapppage', e);
             return false;
         }
@@ -702,7 +702,7 @@ function getapppage(appname, compos) {
         apppage = page;
 
         // Merge in the app data
-        if (!isNil(appcomposite))
+        if (!isNull(appcomposite))
             getappdata(appname, apppage, appcomposite);
 });
 
@@ -720,10 +720,10 @@ function compquery() {
         return append(nodeList(n.childNodes), reduce(append, mklist(), map(childrenList, nodeList(n.childNodes))));
     }
 
-    var args = map(queryarg, filter(function(e) { return !isNil(e.id) && !isNil(inputvalue(e)); }, childrenList(ui.elementByID(contentdiv, 'page'))));
+    var args = map(queryarg, filter(function(e) { return !isNull(e.id) && !isNull(inputvalue(e)); }, childrenList(ui.elementByID(contentdiv, 'page'))));
 
     // Append current location properties if known
-    if (!isNil(geoposition)) {
+    if (!isNull(geoposition)) {
         var g = geoposition;
         args = append(args, mklist('latitude=' + g.coords.latitude, 'longitude=' + g.coords.longitude, 'altitude=' + g.coords.altitude,
                         'accuracy=' + g.coords.accuracy, 'altitudeAccuracy=' + g.coords.altitudeAccuracy, 'heading=' + g.coords.heading,
@@ -740,7 +740,7 @@ function buttonClickHandler(id, appname) {
     try {
         var uri = compquery();
         return sca.component(id, appname).get(uri, function(doc, e) {
-            if (isNil(doc)) {
+            if (isNull(doc)) {
                 debug('error on get(button, ' + uri + ')', e);
                 return false;
             }
@@ -761,7 +761,7 @@ function intervalHandler() {
     try {
         var uri = compquery();
         return timercomp.get(uri, function(doc, e) {
-            if (isNil(doc)) {
+            if (isNull(doc)) {
                 debug('error on get(timer, ' + uri + ')', e);
                 return false;
             }
@@ -804,7 +804,7 @@ function animationHandler() {
             updatepage(car(currentAnimationData));
 
             // End of animation?
-            if (isNil(cdr(currentAnimationData))) {
+            if (isNull(cdr(currentAnimationData))) {
                 if (currentAnimationLoop == -1) {
                     // Repeat current animation forever
                     currentAnimationData = animationData;
@@ -830,12 +830,12 @@ function animationHandler() {
         }
 
         // Get new animation data if necessary
-        if (isNil(animationData)) {
+        if (isNull(animationData)) {
             if (gettingAnimationData)
                 return true;
             var uri = compquery();
             return animationcomp.get(uri, function(doc, e) {
-                if (isNil(doc)) {
+                if (isNull(doc)) {
                     debug('error on get(animation, ' + uri + ')', e);
                     return false;
                 }
@@ -882,7 +882,7 @@ function locationHandler(pos) {
         geoposition = pos;
         var uri = compquery();
         return locationcomp.get(uri, function(doc, e) {
-            if (isNil(doc)) {
+            if (isNull(doc)) {
                 debug('error on get(location, ' + uri + ')', e);
                 return false;
             }
@@ -897,7 +897,7 @@ function locationHandler(pos) {
 
 function locationErrorHandler(e) {
     debug('location error', e);
-    if (!isNil(locationWatch)) {
+    if (!isNull(locationWatch)) {
         try {
             navigator.geolocation.clearWatch(locationWatch);
         } catch(e) {}
@@ -911,7 +911,7 @@ function locationErrorHandler(e) {
  */
 function setupLocationHandler() {
     function installLocationHandler() {
-        if (!isNil(locationWatch))
+        if (!isNull(locationWatch))
             return true;
         try {
             locationWatch = navigator.geolocation.watchPosition(locationHandler, locationErrorHandler);
@@ -940,7 +940,7 @@ document.body.onorientationchange = function(e) {
  */
 function atomcomposite(doc) {
     var entry = atom.readATOMEntry(mklist(doc));
-    if (isNil(entry))
+    if (isNull(entry))
         return mklist();
     var content = namedElementChild("'content", car(entry));
     if (content == null)
@@ -954,13 +954,13 @@ function atomcomposite(doc) {
 function getappcomposite(appname) {
     return composcomp.get(appname, function(doc, e) {
         //debug('page get');
-        if (isNil(doc)) {
+        if (isNull(doc)) {
             debug('error in getappcomposite', e);
             return false;
         }
 
         var compos = atomcomposite(doc);
-        if (isNil(compos)) {
+        if (isNull(compos)) {
 
             // Create a default empty composite if necessary
             var x = '<composite xmlns="http://docs.oasis-open.org/ns/opencsa/sca/200912" ' +
@@ -970,7 +970,7 @@ function getappcomposite(appname) {
         appcomposite = compos;
 
         // Merge in the app data
-        if (!isNil(apppage))
+        if (!isNull(apppage))
             getappdata(appname, apppage, appcomposite);
     });
 }
diff --git a/sca-cpp/trunk/hosting/server/htdocs/clone/index.html b/sca-cpp/trunk/hosting/server/htdocs/clone/index.html
index c6a9658ce0..e9de1be1fb 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/clone/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/clone/index.html
@@ -72,7 +72,7 @@ var savedappxml = '';
  * Get and display the requested app.
  */
 (function getapp() {
-    if (isNil(appname))
+    if (isNull(appname))
         return false;
     workingstatus(true);
     showstatus('Loading');
@@ -149,7 +149,7 @@ $('cloneAppForm').onsubmit = function() {
 
     // Check reserved app names
     var reserved = mklist('account', 'app', 'cache', 'clone', 'create', 'delete', 'graph', 'home', 'login', 'new', 'page', 'proxy', 'public', 'private', 'info', 'store');
-    if (!isNil(assoc(name, map(function(r) { return mklist(r, r); }, reserved)))) {
+    if (!isNull(assoc(name, map(function(r) { return mklist(r, r); }, reserved)))) {
         errorstatus('App name is taken, please pick another name');
         return false;
     }
diff --git a/sca-cpp/trunk/hosting/server/htdocs/config.js b/sca-cpp/trunk/hosting/server/htdocs/config.js
index 355174e6f7..20212980f0 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/config.js
+++ b/sca-cpp/trunk/hosting/server/htdocs/config.js
@@ -17,7 +17,7 @@
  * under the License.    
  */
 
-if (isNil(config))
+if (isNull(config))
     config = {};
 
 /**
diff --git a/sca-cpp/trunk/hosting/server/htdocs/create/index.html b/sca-cpp/trunk/hosting/server/htdocs/create/index.html
index a11c0958f5..3fc26b8515 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/create/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/create/index.html
@@ -114,7 +114,7 @@ $('createAppForm').onsubmit = function() {
 
     // Check reserved app names
     var reserved = mklist('account', 'app', 'cache', 'clone', 'create', 'delete', 'graph', 'home', 'login', 'new', 'page', 'proxy', 'public', 'private', 'info', 'store');
-    if (!isNil(assoc(name, map(function(r) { return mklist(r, r); }, reserved)))) {
+    if (!isNull(assoc(name, map(function(r) { return mklist(r, r); }, reserved)))) {
         errorstatus('App name is taken, please pick another name');
         return false;
     }
diff --git a/sca-cpp/trunk/hosting/server/htdocs/delete/index.html b/sca-cpp/trunk/hosting/server/htdocs/delete/index.html
index 81cfa0b625..3855a09e3c 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/delete/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/delete/index.html
@@ -83,7 +83,7 @@ var appentry;
  * Get and display the requested app.
  */
 (function getapp() {
-    if (isNil(appname))
+    if (isNull(appname))
         return false;
     workingstatus(true);
     showstatus('Loading');
@@ -103,7 +103,7 @@ var appentry;
         $('appUpdated').value = xmldatetime(cadr(assoc("'updated", appentry))).toLocaleDateString();
         var content = cadr(assoc("'content", appentry));
         var description = assoc("'description", content);
-        $('appDescription').value = isNil(description) || isNil(cadr(description))? '' : cadr(description);
+        $('appDescription').value = isNull(description) || isNull(cadr(description))? '' : cadr(description);
 
         onlinestatus();
         workingstatus(false);
diff --git a/sca-cpp/trunk/hosting/server/htdocs/graph/index.html b/sca-cpp/trunk/hosting/server/htdocs/graph/index.html
index d01bfa1c02..557f427e38 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/graph/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/graph/index.html
@@ -32,11 +32,11 @@
  */
 var appname = ui.fragmentParams(location)['app'];
 var ispalette = false;
-if (isNil(appname)) {
+if (isNull(appname)) {
     appname = ui.fragmentParams(location)['palette'];
 
     // Edit a palette instead of a regular app
-    if (!isNil(appname))
+    if (!isNull(appname))
         ispalette = true;
 }
 
@@ -179,7 +179,7 @@ graph.mkedit = function(graphdiv, pos, atitle, cvalue, cadd, ccopy, cdelete, onc
         //debug('draggable', n);
         if (n == graphdiv || n == null)
             return null;
-        if (n.className == 'g' && !isNil(n.id) && n.id != '')
+        if (n.className == 'g' && !isNull(n.id) && n.id != '')
             return n;
         return draggable(n.parentNode);
     }
@@ -301,7 +301,7 @@ graph.mkedit = function(graphdiv, pos, atitle, cvalue, cadd, ccopy, cdelete, onc
         if (graph.dragging.parentNode == graphdiv && graph.dragging.id.substring(0, 8) != 'palette:') {
 
             // Add new dragged component to the composite
-            if (isNil(graph.dragging.compos)) {
+            if (isNull(graph.dragging.compos)) {
                 var compos = scdl.composite(graphdiv.compos);
                 setElement(compos, graph.sortcompos(graph.addcomps(mklist(graph.dragging.comp), compos)));
                 graph.dragging.compos = graphdiv.compos;
@@ -311,7 +311,7 @@ graph.mkedit = function(graphdiv, pos, atitle, cvalue, cadd, ccopy, cdelete, onc
             setElement(graph.dragging.comp, graph.movecomp(graph.dragging.comp, graph.abspos(graph.draggingg)));
 
             // Wire component to neighboring reference
-            if (!isNil(graph.dragging.svcpos)) {
+            if (!isNull(graph.dragging.svcpos)) {
                 var compos = scdl.composite(graphdiv.compos);
                 setElement(compos, graph.sortcompos(graph.clonerefs(graph.wire(graph.dragging, compos, graphdiv))));
             }
@@ -332,7 +332,7 @@ graph.mkedit = function(graphdiv, pos, atitle, cvalue, cadd, ccopy, cdelete, onc
         var nodes = graph.refresh(graphdiv);
 
         // Reselect the previously selected component
-        if (!isNil(graph.selected)) {
+        if (!isNull(graph.selected)) {
             graph.selected = graph.findcompnode(scdl.name(graph.selected.comp), nodes);
             graph.compselect(graph.selected, true, atitle, cvalue, ccopy, cdelete);
 
@@ -544,7 +544,7 @@ graph.mkedit = function(graphdiv, pos, atitle, cvalue, cadd, ccopy, cdelete, onc
 
             // Remove selected component
             var compos = scdl.composite(graphdiv.compos);
-            if (isNil(graph.selected.compos))
+            if (isNull(graph.selected.compos))
                 setElement(compos, graph.sortcompos(graph.cutwire(graph.selected, compos, graphdiv)));
             setElement(compos, graph.sortcompos(graph.clonerefs(graph.gcollect(graph.removecomp(graph.selected.comp, compos)))));
 
@@ -752,8 +752,8 @@ graph.drawshape = function(g) {
 
     // Draw the shape
     ctx.fillStyle = g.fillStyle;
-    ctx.strokeStyle = !isNil(g.strokeStyle)? g.strokeStyle : graph.colors.gray;
-    ctx.lineWidth = !isNil(g.lineWidth)? g.lineWidth : 1;
+    ctx.strokeStyle = !isNull(g.strokeStyle)? g.strokeStyle : graph.colors.gray;
+    ctx.lineWidth = !isNull(g.lineWidth)? g.lineWidth : 1;
     g.path.draw(ctx);
 
     // Reset canvas context
@@ -794,7 +794,7 @@ graph.comptitle = function(comp) {
  */
 graph.comptitlewidth = function(comp) {
     var title = graph.comptitle(comp);
-    if (isNil(title))
+    if (isNull(title))
         return 0;
     return title.clientWidth;
 };
@@ -803,14 +803,14 @@ graph.comptitlewidth = function(comp) {
  * Draw a component shape selection.
  */
 graph.compselect = function(g, s, atitle, cvalue, ccopy, cdelete) {
-    if (isNil(g) || !s) {
+    if (isNull(g) || !s) {
         cvalue.value = '';
         cvalue.readOnly = true;
         cvalue.style.display = 'none';
         atitle.style.display = 'block';
         ccopy.disabled = true;
         cdelete.disabled = true;
-        if (isNil(g))
+        if (isNull(g))
             return true;
         g.shape.strokeStyle = null;
         g.shape.lineWidth = null;
@@ -836,7 +836,7 @@ graph.compselect = function(g, s, atitle, cvalue, ccopy, cdelete) {
  * Draw a palette shape selection.
  */
 graph.paletteselect = function(g, s) {
-    if (isNil(g))
+    if (isNull(g))
         return true;
     if (!s) {
         g.shape.strokeStyle = null;
@@ -879,7 +879,7 @@ graph.compnode = function(comp, cassoc, pos) {
     g.shape = shape;
     g.style.width = ui.pixpos(shape.width);
     g.style.height = ui.pixpos(shape.height);
-    if (!isNil(title)) {
+    if (!isNull(title)) {
         title.style.left = ui.pixpos(shape.path.xmin * -1);
         g.appendChild(title);
     }
@@ -895,14 +895,14 @@ graph.compnode = function(comp, cassoc, pos) {
  * Find the node representing a component.
  */
 graph.findcompnode = function(name, nodes) {
-    if (isNil(nodes))
+    if (isNull(nodes))
         return null;
-    if (isNil(car(nodes).comp))
+    if (isNull(car(nodes).comp))
         return graph.findcompnode(name, cdr(nodes));
     if (name == scdl.name(car(nodes).comp))
         return car(nodes);
     var node = graph.findcompnode(name, nodeList(car(nodes).childNodes));
-    if (!isNil(node))
+    if (!isNull(node))
         return node;
     return graph.findcompnode(name, cdr(nodes));
 }
@@ -969,7 +969,7 @@ graph.move = function(g, pos) {
  * Return the absolute position of a component node.
  */
 graph.abspos = function(e) {
-    if (isNil(e) || e == graphdiv)
+    if (isNull(e) || e == graphdiv)
         return graph.mkpath();
     var gpos = graph.relpos(e);
     var pgpos = graph.abspos(e.parentNode);
@@ -1010,7 +1010,7 @@ graph.title = function(e) {
  */
 graph.property = function(e) {
     var p = scdl.properties(e);
-    if (isNil(p))
+    if (isNull(p))
         return '';
     if (scdl.visible(car(p)) == 'false')
         return '';
@@ -1034,7 +1034,7 @@ graph.propertytitle = function(e) {
  */
 graph.hasproperty = function(e) {
     var p = scdl.properties(e);
-    if (isNil(p))
+    if (isNull(p))
         return false;
     if (scdl.visible(car(p)) == 'false')
         return false;
@@ -1046,7 +1046,7 @@ graph.hasproperty = function(e) {
  */
 graph.setproperty = function(e, value) {
     var p = scdl.properties(e);
-    if (isNil(p))
+    if (isNull(p))
         return '';
     if (scdl.visible(car(p)) == 'false')
         return '';
@@ -1071,14 +1071,14 @@ graph.color = function(comp) {
 graph.lsvcs = function(comp) {
     return memo(comp, 'lsvcs', function() {
         var svcs = scdl.services(comp);
-        if (isNil(svcs))
+        if (isNull(svcs))
             return mklist(mklist("'element","'service","'attribute","'name",scdl.name(comp)));
         var l = filter(function(s) {
                 var a = scdl.align(s);
                 var v = scdl.visible(s);
                 return (a == null || a == 'left') && v != 'false';
             }, svcs);
-        if (isNil(l))
+        if (isNull(l))
             return mklist();
         return mklist(car(l));
     });
@@ -1103,7 +1103,7 @@ graph.rrefs = function(comp) {
 graph.rrefheight = function(ref, cassoc) {
     return memo(ref, 'rheight', function() {
         var target = assoc(scdl.target(ref), cassoc);
-        if (isNil(target))
+        if (isNull(target))
             return graph.tabsz * 8;
         return graph.compclosureheight(cadr(target), cassoc);
     });
@@ -1113,7 +1113,7 @@ graph.rrefheight = function(ref, cassoc) {
  * Return the total height of the references on the right side of a component.
  */
 graph.rrefsheight = function(refs, cassoc) {
-    if (isNil(refs))
+    if (isNull(refs))
         return 0;
     return graph.rrefheight(car(refs), cassoc) + graph.rrefsheight(cdr(refs), cassoc);
 };
@@ -1144,7 +1144,7 @@ graph.compclosureheight = function(comp, cassoc) {
  * Return the max width of the references on the right side of a component.
  */
 graph.rrefswidth = function(refs, cassoc) {
-    if (isNil(refs))
+    if (isNull(refs))
         return 0;
     return Math.max(graph.rrefwidth(car(refs), cassoc), graph.rrefswidth(cdr(refs), cassoc));
 };
@@ -1155,7 +1155,7 @@ graph.rrefswidth = function(refs, cassoc) {
 graph.compwidth = function(comp, cassoc) {
     return memo(comp, 'width', function() {
         var ctw = graph.comptitlewidth(comp);
-        var rrefsw = (isNil(graph.rrefs(comp))? 0 : (graph.tabsz * 4));
+        var rrefsw = (isNull(graph.rrefs(comp))? 0 : (graph.tabsz * 4));
         var twidth = (graph.titlex * 2) + ctw + rrefsw;
         var width = Math.max(twidth, (graph.tabsz * 8) + (graph.tabsz * 4));
         return width;
@@ -1205,7 +1205,7 @@ graph.comppath = function(comp, cassoc) {
      * Apply a path rendering function to a list of services or references.
      */
     function renderpath(x, f, cassoc, path, height) {
-        if (isNil(x))
+        if (isNull(x))
             return path;
         return renderpath(cdr(x), f, cassoc, f(car(x), cassoc, path, height), height);
     }
@@ -1290,7 +1290,7 @@ graph.composite = function(compos, pos, aspalette) {
              */
             function renderrref(ref, cassoc, pos, gcomp) {
                 var target = assoc(scdl.target(ref), cassoc);
-                if (isNil(target))
+                if (isNull(target))
                     return null;
 
                 // Render the component target of the reference
@@ -1304,7 +1304,7 @@ graph.composite = function(compos, pos, aspalette) {
                 return pos.clone().rmove(0, graph.rrefheight(ref, cassoc));
             }
 
-            if (isNil(refs))
+            if (isNull(refs))
                 return mklist();
 
             // Return list of (ref, comp rendering) pairs
@@ -1322,7 +1322,7 @@ graph.composite = function(compos, pos, aspalette) {
 
         // Store list of (ref, pos, component rendering) triplets in the component
         function refposgcomp(refpos, grefs) {
-            if (isNil(refpos))
+            if (isNull(refpos))
                 return mklist();
 
             // Append component rendering to component
@@ -1347,7 +1347,7 @@ graph.composite = function(compos, pos, aspalette) {
          */
         function promcomp(svc, cassoc) {
             var c = assoc(scdl.promote(svc), cassoc);
-            if (isNil(c))
+            if (isNull(c))
                 return mklist();
             return cadr(c);
         }
@@ -1359,13 +1359,13 @@ graph.composite = function(compos, pos, aspalette) {
             return pos.clone().rmove(0, graph.compclosureheight(comp, cassoc) + Math.max((graph.tabsz * 2), 8));
         }
 
-        if (isNil(svcs))
+        if (isNull(svcs))
             return mklist();
 
         // Render the first promoted component in the list
         // then recurse to render the rest of the list
         var comp = promcomp(car(svcs), cassoc);
-        if (isNil(comp))
+        if (isNull(comp))
             return renderproms(cdr(svcs), cassoc, rendermove(car(svcs), cassoc, pos));
 
         var cpos = graph.comppos(comp, pos);
@@ -1401,14 +1401,14 @@ graph.ucid = function(prefix, compos1, compos2, clone) {
     // Build an assoc list keyed by component name
     var comps = map(function(c) { return mklist(scdl.name(c), c); }, append(namedElementChildren("'component", compos1), namedElementChildren("'component", compos2)));
 
-    if (!clone && isNil(assoc(prefix, comps)))
+    if (!clone && isNull(assoc(prefix, comps)))
         return prefix;
 
     /**
      * Find a free component id.
      */
     function ucid(p, id) {
-        if (isNil(assoc(p + id, comps)))
+        if (isNull(assoc(p + id, comps)))
             return p + id;
         return ucid(p, id + 1);
     }
@@ -1447,7 +1447,7 @@ graph.clonepalette = function(e, compos) {
  * Move a SCDL component to the given position.
  */
 graph.movecomp = function(comp, pos) {
-    if (isNil(pos))
+    if (isNull(pos))
         return append(mklist(element, "'component"),
                 filter(function(e) { return !(isAttribute(e) && (attributeName(e) == "'x" || attributeName(e) == "'y")); }, elementChildren(comp)));
     return append(mklist(element, "'component", mklist(attribute, "'x", '' + (pos.x - graph.palcx)), mklist(attribute, "'y", '' + pos.y)),
@@ -1469,11 +1469,11 @@ graph.clonecomp = function(e, compos) {
     // Write the component and the components it references to XML
     function collectcomp(e) {
         function collectrefs(refpos) {
-            if (isNil(refpos))
+            if (isNull(refpos))
                 return mklist();
             var r = car(refpos);
             var n = caddr(r);
-            if (isNil(n))
+            if (isNull(n))
                 return collectrefs(cdr(refpos));
             return append(collectcomp(n), collectrefs(cdr(refpos)));
         }
@@ -1578,7 +1578,7 @@ graph.gcollect = function(compos) {
     // Filter out the unused components
     var used = append(proms, refs);
     return append(mklist(element, "'composite"),
-            filter(function(c) { return !(isElement(c) && elementName(c) == "'component" && isNil(assoc(scdl.name(c), used))); }, elementChildren(compos)));
+            filter(function(c) { return !(isElement(c) && elementName(c) == "'component" && isNull(assoc(scdl.name(c), used))); }, elementChildren(compos)));
 }
 
 /**
@@ -1592,7 +1592,7 @@ graph.clonerefs = function(compos) {
 
                 // If the references are clonable
                 var refs = scdl.references(c);
-                if (isNil(refs))
+                if (isNull(refs))
                     return c;
                 if (scdl.clonable(car(refs)) != 'true')
                     return c;
@@ -1611,7 +1611,7 @@ graph.clonerefs = function(compos) {
  * Refactor references to a component.
  */
 graph.refactorrefs = function(refs, oname, nname) {
-    if (isNil(refs))
+    if (isNull(refs))
         return true;
     var ref = car(refs);
     if (scdl.target(ref) != oname)
@@ -1636,7 +1636,7 @@ graph.renamecomp = function(comp, compos, name) {
 
     // Rename the SCDL promoted service and component
     var proms = filter(function(s) { return scdl.name(s) == oname }, scdl.services(compos));
-    if (!isNil(proms))
+    if (!isNull(proms))
         setElement(car(proms), mklist(element, "'service", mklist(attribute, "'name", name), mklist(attribute, "'promote", name)));
     setElement(comp, append(mklist(element, "'component"),
         cons(mklist(attribute, "'name", name),
@@ -1655,7 +1655,7 @@ graph.cutwire = function(node, compos, g) {
      * Find the reference wired to a node and cut its wire.
      */
     function cutref(refs, node) {
-        if (isNil(refs))
+        if (isNull(refs))
             return true;
         var ref = car(refs);
         if (caddr(ref) == node) {
@@ -1702,13 +1702,13 @@ graph.wire = function(n, compos, g) {
          * references of a node.
          */
         function closerefs(npos, refs, spos, cref) {
-            if (isNil(refs))
+            if (isNull(refs))
                 return cref;
             var fdist = cadddr(cref);
             var ref = car(refs);
 
             // Skip wired reference
-            if (!isNil(filter(function(n) { return isAttribute(n) && attributeName(n) == "'target"; }, car(ref))))
+            if (!isNull(filter(function(n) { return isAttribute(n) && attributeName(n) == "'target"; }, car(ref))))
                 return closerefs(npos, cdr(refs), spos, cref);
 
             // Compute distance between service node and reference node
@@ -1723,12 +1723,12 @@ graph.wire = function(n, compos, g) {
             return closerefs(npos, cdr(refs), spos, fdist < rdist? cref : mklist(car(ref), cadr(ref), caddr(ref), rdist));
         }
 
-        if (isNil(nodes))
+        if (isNull(nodes))
             return cref;
 
         // Skip non-component nodes
         var node = car(nodes);
-        if (isNil(node.comp))
+        if (isNull(node.comp))
             return closecomprefs(cdr(nodes), spos, cref);
 
         // Compute the component absolute position
@@ -1771,7 +1771,7 @@ graph.display = function(nodes, g) {
 graph.hide = function(g) {
 
     // Remove nodes from the graph
-    map(function(n) { if (!isNil(n.comp) && n.id.substr(0, 8) != 'palette:') { g.removeChild(n); } return n; }, nodeList(g.childNodes));
+    map(function(n) { if (!isNull(n.comp) && n.id.substr(0, 8) != 'palette:') { g.removeChild(n); } return n; }, nodeList(g.childNodes));
     return g;
 };
 
@@ -1782,7 +1782,7 @@ graph.refresh = function(g) {
     //debug('refresh');
 
     // Remove existing nodes from the graph
-    map(function(n) { if (!isNil(n.comp) && n.id.substr(0, 8) != 'palette:') { g.removeChild(n); } return n; }, nodeList(g.childNodes));
+    map(function(n) { if (!isNull(n.comp) && n.id.substr(0, 8) != 'palette:') { g.removeChild(n); } return n; }, nodeList(g.childNodes));
 
     // Redisplay the composite associated with the graph
     var nodes = graph.composite(g.compos, graph.mkpath().pos(graph.palcx,0), false);
@@ -1802,7 +1802,7 @@ graph.edit = function(appname, compos, nodes, g) {
     setElement(scompos, graph.sortcompos(scompos));
 
     // Remove existing nodes from the graph
-    map(function(n) { if (!isNil(n.comp) && n.id.substr(0, 8) != 'palette:') { g.removeChild(n); } return n; }, nodeList(g.childNodes));
+    map(function(n) { if (!isNull(n.comp) && n.id.substr(0, 8) != 'palette:') { g.removeChild(n); } return n; }, nodeList(g.childNodes));
 
     // Display the composite nodes
     appendNodes(nodes, g);
@@ -1829,7 +1829,7 @@ var bpalette = null;
  * Get and display an application composite.
  */
 function getapp(name, g) {
-    if (isNil(name))
+    if (isNull(name))
         return false;
     workingstatus(true);
     showstatus('Loading');
@@ -1846,8 +1846,8 @@ function getapp(name, g) {
         // Get the composite from the ATOM entry
         var composentry = car(atom.readATOMEntry(mklist(doc)));
         var content = namedElementChild("'content", composentry);
-        composite = isNil(content)? mklist() : elementChildren(content);
-        if (isNil(composite)) {
+        composite = isNull(content)? mklist() : elementChildren(content);
+        if (isNull(composite)) {
 
             // Create a default empty composite if necessary
             var x = '<composite xmlns="http://docs.oasis-open.org/ns/opencsa/sca/200912" ' +
@@ -1879,15 +1879,15 @@ function getapp(name, g) {
  * Display a palette. Get it from the server if needed.
  */
 function displaypalette(name, g, palette, gpalettes) {
-    if (isNil(name))
+    if (isNull(name))
         return;
-    if (isNil(gpalettes[name])) {
+    if (isNull(gpalettes[name])) {
 
         // Get the palette from the server
         palettes.get(name, function(doc) {
             var entry = car(atom.readATOMEntry(mklist(doc)));
             var content = namedElementChild("'content", entry);
-            var compos = isNil(content)? mklist() : elementChildren(content);
+            var compos = isNull(content)? mklist() : elementChildren(content);
             gpalettes[name] = graph.composite(compos, graph.mkpath().move(2580,0), true, g);
             graph.display(gpalettes[name], g);
         });
@@ -1985,7 +1985,7 @@ function oncomposchange(prop) {
  * Return the link to a component.
  */
 function complink(appname, cname) {
-    if (cname == '' || isNil(cname))
+    if (cname == '' || isNull(cname))
         return '';
     var protocol = location.protocol;
     var host = location.hostname;
@@ -2004,9 +2004,9 @@ function oncompselect(gsel) {
         return true;
     gcomp = gsel;
 
-    cdelete.disabled = isNil(gsel) || !editable;
-    ccopy.disabled = isNil(gsel) || !editable;
-    cplay.disabled = isNil(gsel);
+    cdelete.disabled = isNull(gsel) || !editable;
+    ccopy.disabled = isNull(gsel) || !editable;
+    cplay.disabled = isNull(gsel);
     return true;
 }
 
@@ -2016,7 +2016,7 @@ function oncompselect(gsel) {
 function showdata(gcomp) {
     if (!gvisible)
         return true;
-    if (isNil(gcomp))
+    if (isNull(gcomp))
         return true;
     cvalue.value = complink(appname, gcomp.id);
     cplay.value = '<';
diff --git a/sca-cpp/trunk/hosting/server/htdocs/home/index.html b/sca-cpp/trunk/hosting/server/htdocs/home/index.html
index d7a098e998..b5240bfd11 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/home/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/home/index.html
@@ -60,7 +60,7 @@ $('getstarted').onclick = function() {
  */
 (function homeanimation() {
     var anim = $('homeanimation');
-    if (!isNil(anim)) {
+    if (!isNull(anim)) {
         anim.style.background = 'url(\'' + ui.b64png(appcache.get('/home/home.b64')) + '\')';
         var bgpos = 0;
         setInterval(function homeanimation() {
diff --git a/sca-cpp/trunk/hosting/server/htdocs/index.html b/sca-cpp/trunk/hosting/server/htdocs/index.html
index 6ea6f80939..7722f96e3f 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/index.html
@@ -203,7 +203,7 @@ var appresources = [
  * Init status message area.
  */
 (function initstatus() {
-    if (isNil($('status')))
+    if (isNull($('status')))
         return;
     $('status').style.display = 'none';
     
@@ -221,7 +221,7 @@ var appresources = [
  */
 window.showstatus = function(s, c) {
     //debug('show status', s);
-    if (isNil($('status')) || $('status').error)
+    if (isNull($('status')) || $('status').error)
         return s;
     $('status').innerHTML = '<span class="' + (c? c : 'okstatus') + '">' + s + '</span>';
     $('status').className = ui.isMobile()? 'status3dm' : 'status3d';
@@ -249,7 +249,7 @@ window.errorstatus = function(s) {
  */
 window.workingstatus = function(w, c) {
     //debug('show working', w);
-    if (isNil($('working')))
+    if (isNull($('working')))
         return w;
     if (!ui.isMobile())
         $('working').style.top = ui.pixpos(Math.round(window.clientHeight / 2));
@@ -286,10 +286,10 @@ map(function(res) {
  */
 function viewtransition(ouri, uri) {
     var ot = apptransitions[ouri];
-    if (isNil(ot))
+    if (isNull(ot))
         return 'left';
     var t = apptransitions[uri];
-    if (isNil(t))
+    if (isNull(t))
         return 'left';
     return t < ot? 'right' : 'left';
 }
@@ -330,7 +330,7 @@ function showmenu(view, appname) {
         append(mklist(ui.menu('menuhome', 'Home', '/', '_view', view == 'home'),
                     ui.menu('menustore', 'Store', '/#view=store&category=' + storecat + '&idx=' + storeidx, '_view', view == 'store'),
                     ui.menu('menusearch', 'Search', '/#view=search', '_view', view == 'search')),
-                (isNil(appname) || appname == 'undefined')?
+                (isNull(appname) || appname == 'undefined')?
                     mklist() :
                     mklist(
                         ui.menu('menuinfo', 'Info', '/#view=info&app=' + appname, '_view', view == 'info'),
@@ -341,7 +341,7 @@ function showmenu(view, appname) {
                         ui.menu('menurun', '<span class="greentext" style="font-weight: bold">Run!</span>', '/' + appname + '/', '_blank', false)
                         */
                         )),
-        (isNil(appname) || appname == 'undefined')? mklist(
+        (isNull(appname) || appname == 'undefined')? mklist(
             ui.menufunc('menusignout', 'Sign out', 'return logout();', false),
             ui.menu('menuaccount', 'Account', '/#view=account', '_view', view == 'account')) :
             mklist());
@@ -376,13 +376,13 @@ function showview(url) {
 
     // Determine the view to show
     var params = ui.fragmentParams(url);
-    var view = isNil(params['view'])? 'home' : params['view'];;
+    var view = isNull(params['view'])? 'home' : params['view'];;
     var uri = '/' + view + '/';
-    var idx = isNil(params['idx'])? 0 : parseInt(params['idx']);
+    var idx = isNull(params['idx'])? 0 : parseInt(params['idx']);
 
     // Track store category view
     if (view == 'store') {
-        storecat = isNil(params['category'])? 'top' : params['category'];
+        storecat = isNull(params['category'])? 'top' : params['category'];
         storeidx = idx;
     }
 
@@ -406,7 +406,7 @@ function showview(url) {
     if (ui.isMobile()) {
         // Prepare current view for transition out
         var ovdiv = viewdiv;
-        if (!isNil(ovdiv)) {
+        if (!isNull(ovdiv)) {
             ovdiv.skipNode = true;
             ovdiv.className = 'viewunloading3dm';
         }
@@ -420,7 +420,7 @@ function showview(url) {
 
         ui.async(function mtransitionview() {
             // Transition the old view out
-            if (!isNil(ovdiv))
+            if (!isNull(ovdiv))
                 ovdiv.className = vtransition + 'viewunloaded3dm';
 
             // Transition the new view in
@@ -430,7 +430,7 @@ function showview(url) {
     } else {
         // Prepare current view for transition out
         var ovdiv = viewdiv;
-        if (!isNil(ovdiv))
+        if (!isNull(ovdiv))
             ovdiv.skipNode = true;
 
         // Load the requested doc into the view
@@ -445,7 +445,7 @@ function showview(url) {
             vdiv.className = 'viewloaded3d';
 
             // Transition the old view out
-            if (!isNil(ovdiv))
+            if (!isNull(ovdiv))
                 ovdiv.parentNode.removeChild(ovdiv);
         });
     }
@@ -649,7 +649,7 @@ document.body.onorientationchange = function(e) {
                     appcache.remove(res[0]);
                     appcache.get(res[0], 'remote');
                 }, append(appresources, config.appresources()));
-                if (!isNil(lcmf)) {
+                if (!isNull(lcmf)) {
                     //debug('reloading');
                     window.location.reload();
                 }
@@ -697,7 +697,7 @@ window.onload = function() {
         document.referrer.indexOf('//accounts.google.com/ServiceLogin') != -1 ||
         document.referrer.indexOf('//www.facebook.com/login.php') != -1)) {
         var lv = lastvisited();
-        var url = isNil(lv)? location.pathname : lv;
+        var url = isNull(lv)? location.pathname : lv;
         updatelocation(url);
         if (url == viewurl)
             return true;
diff --git a/sca-cpp/trunk/hosting/server/htdocs/info/index.html b/sca-cpp/trunk/hosting/server/htdocs/info/index.html
index 0d72062719..3038d37cf2 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/info/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/info/index.html
@@ -100,7 +100,7 @@ var savediconxml;
  * Get and display the requested app.
  */
 (function getapp() {
-    if (isNil(appname))
+    if (isNull(appname))
         return false;
     workingstatus(true);
     showstatus('Loading');
@@ -118,10 +118,10 @@ var savediconxml;
         author = cadr(assoc("'author", appentry));
         $('appAuthor').value = author.split('@')[0];
         var updated = assoc("'updated", appentry);
-        $('appUpdated').value = isNil(updated)? '' : xmldatetime(cadr(updated)).toLocaleDateString();
+        $('appUpdated').value = isNull(updated)? '' : xmldatetime(cadr(updated)).toLocaleDateString();
         var content = cadr(assoc("'content", appentry));
         var description = assoc("'description", content);
-        $('appDescription').value = isNil(description) || isNil(cadr(description))? '' : cadr(description);
+        $('appDescription').value = isNull(description) || isNull(cadr(description))? '' : cadr(description);
         //var ratingy = -20 * (4 - Math.floor(Math.random() * 4));
         //$('appRating').style.backgroundPosition = '0px ' + ratingy + 'px';
         //$('appRatings').value = '';
@@ -165,7 +165,7 @@ var savediconxml;
         var content = assoc("'content", picentry);
         var picture = assoc("'picture", content);
         var img = assoc("'image", picture);
-        if (!isNil(img))
+        if (!isNull(img))
             $('authorPicture').src = cadr(img);
 
         onlinestatus();
@@ -179,7 +179,7 @@ var savediconxml;
  * Get and display the app icon.
  */
 (function geticon() {
-    if (isNil(appname))
+    if (isNull(appname))
         return false;
     workingstatus(true);
     showstatus('Loading');
@@ -197,7 +197,7 @@ var savediconxml;
         var content = assoc("'content", iconentry);
         var icon = assoc("'icon", content);
         var img = assoc("'image", icon);
-        if (!isNil(img))
+        if (!isNull(img))
             $('appIcon').src = cadr(img);
 
         onlinestatus();
@@ -212,7 +212,7 @@ var savediconxml;
  */
 var refreshingicon = false;
 function refreshicon() {
-    if (isNil(appname))
+    if (isNull(appname))
         return false;
     if (!refreshingicon)
         return false;
@@ -231,11 +231,11 @@ function refreshicon() {
         var token = assoc("'token", icon);
 
         // Update icon
-        if (isNil(token)) {
+        if (isNull(token)) {
             var entryxml = car(atom.writeATOMEntry(valuesToElements(mklist(iconentry))));
             savediconxml = entryxml;
             var img = assoc("'image", icon);
-            if (!isNil(img))
+            if (!isNull(img))
                 $('appIcon').src = cadr(img);
             $('refreshingIcon').style.display = 'none';
             refreshingicon = false;
@@ -252,7 +252,7 @@ function refreshicon() {
  * Get and display the app ratings.
  */
 (function getratings() {
-    if (isNil(appname))
+    if (isNull(appname))
         return false;
     workingstatus(true);
     showstatus('Loading');
@@ -272,8 +272,8 @@ function refreshicon() {
         var ar2 = assoc("'rating2", aratings);
         var ar3 = assoc("'rating3", aratings);
         var ar4 = assoc("'rating4", aratings);
-        var rating = isNil(ar)? 0 : Number(cadr(ar));
-        var reviews = (isNil(ar1)? 0 : Number(cadr(ar1))) + (isNil(ar2)? 0 : Number(cadr(ar2))) + (isNil(ar3)? 0 : Number(cadr(ar3))) + (isNil(ar4)? 0 : Number(cadr(ar4)));
+        var rating = isNull(ar)? 0 : Number(cadr(ar));
+        var reviews = (isNull(ar1)? 0 : Number(cadr(ar1))) + (isNull(ar2)? 0 : Number(cadr(ar2))) + (isNull(ar3)? 0 : Number(cadr(ar3))) + (isNull(ar4)? 0 : Number(cadr(ar4)));
 
         var ratingy = -20 * (4 - Math.floor(rating));
         $('appRating').style.backgroundPosition = '0px ' + ratingy + 'px';
diff --git a/sca-cpp/trunk/hosting/server/htdocs/login/index.html b/sca-cpp/trunk/hosting/server/htdocs/login/index.html
index efc3feaeaa..93d47d3f28 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/login/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/login/index.html
@@ -212,7 +212,7 @@ try {
  * Initialize status message area.
  */
 (function initstatus() {
-    if (isNil($('status')))
+    if (isNull($('status')))
         return;
     $('status').style.display = 'none';
     
@@ -230,7 +230,7 @@ try {
  */
 window.showstatus = function(s, c) {
     //debug('show status', s);
-    if (isNil($('status')) || $('status').error)
+    if (isNull($('status')) || $('status').error)
         return s;
     $('status').innerHTML = '<span class="' + (c? c : 'okstatus') + '">' + s + '</span>';
     $('status').className = ui.isMobile()? 'status3dm' : 'status3d';
@@ -258,7 +258,7 @@ window.errorstatus = function(s) {
  */
 window.workingstatus = function(w, c) {
     //debug('show working', w);
-    if (isNil($('working')))
+    if (isNull($('working')))
         return w;
     if (!ui.isMobile())
         $('working').style.top = ui.pixpos(Math.round(window.clientHeight / 2));
@@ -469,7 +469,7 @@ var appresources = [
                     appcache.remove(res[0]);
                     appcache.get(res[0], 'remote');
                 }, append(appresources, config.appresources()));
-                if (!isNil(lcmf)) {
+                if (!isNull(lcmf)) {
                     //debug('reloading');
                     window.location.reload();
                 }
diff --git a/sca-cpp/trunk/hosting/server/htdocs/page/index.html b/sca-cpp/trunk/hosting/server/htdocs/page/index.html
index c6e1108ce5..ca89ed34db 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/page/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/page/index.html
@@ -132,7 +132,7 @@ var pages = sca.reference(editorComp, 'pages');
  */
 var msiefixupbounds = ui.isMSIE();
 function widgettransform(e) {
-    if (!isNil(e.xtranslate))
+    if (!isNull(e.xtranslate))
         return [e.xtranslate, e.ytranslate];
     var t = e.style.getPropertyValue('-webkit-transform') || e.style.getPropertyValue('-moz-transform') ||
             e.style.getPropertyValue('-ms-transform') || e.style.getPropertyValue('-o-transform') ||
@@ -156,7 +156,7 @@ function widgettransform(e) {
  */
 function widgetxpos(e) {
     var t = widgettransform(e)[0];
-    return ui.numpos(e.style.left) + (isNil(t)? 0 : t);
+    return ui.numpos(e.style.left) + (isNull(t)? 0 : t);
 }
 
 /**
@@ -164,7 +164,7 @@ function widgetxpos(e) {
  */
 function widgetypos(e) {
     var t = widgettransform(e)[1];
-    return ui.numpos(e.style.top) + (isNil(t)? 0 : t);
+    return ui.numpos(e.style.top) + (isNull(t)? 0 : t);
 }
 
 /**
@@ -290,7 +290,7 @@ function clonewidget(e) {
  */
 function selectwidget(n, s) {
     //debug('selectwidget', n, s);
-    if (isNil(n) || !s) {
+    if (isNull(n) || !s) {
         // Clear the widget value field
         $('widgetValue').value = '';
         $('widgetValue').readOnly = true;
@@ -304,7 +304,7 @@ function selectwidget(n, s) {
         $('deleteWidgetButton').disabled = true;
 
         // Clear the widget outline
-        if (!isNil(n))
+        if (!isNull(n))
             n.style.removeProperty('outline');
         return true;
     }
@@ -422,44 +422,44 @@ function setwidgettext(e, t) {
     e.id = f != ''? f.substring(1) : ('page:' + wc);
 
     if (wc == 'hd1' || wc == 'hd2' || wc == 'text' || wc == 'section') {
-        car(childElements(e)).innerHTML = isNil(c)? f : car(c);
+        car(childElements(e)).innerHTML = isNull(c)? f : car(c);
         return t;
     }
     if (wc == 'button') {
-        car(childElements(e)).value = isNil(c)? f : car(c);
+        car(childElements(e)).value = isNull(c)? f : car(c);
         return t;
     }
     if (wc == 'entry' || wc == 'password') {
-        car(childElements(e)).defaultValue = isNil(c)? f : car(c);
+        car(childElements(e)).defaultValue = isNull(c)? f : car(c);
         return t;
     }
     if (wc == 'checkbox') {
-        car(childElements(e)).value = isNil(c)? f : car(c);
-        map(function(n) { if (n.nodeName == "SPAN") n.innerHTML = isNil(c)? f : car(c); return n; }, nodeList(e.childNodes));
+        car(childElements(e)).value = isNull(c)? f : car(c);
+        map(function(n) { if (n.nodeName == "SPAN") n.innerHTML = isNull(c)? f : car(c); return n; }, nodeList(e.childNodes));
         return t;
     }
     if (wc == 'select') {
         var ce = car(childElements(car(childElements(e))));
-        ce.value = isNil(c)? f : car(c);
-        ce.innerHTML = isNil(c)? f : car(c);
+        ce.value = isNull(c)? f : car(c);
+        ce.innerHTML = isNull(c)? f : car(c);
         return t;
     }
     if (wc == 'list') {
-        e.innerHTML = '<table class="datatable" style="width: 100%;;"><tr><td class="datatd">' + (isNil(c)? f : car(c)) + '</td></tr><tr><td class="datatd">...</td></tr></table>';
+        e.innerHTML = '<table class="datatable" style="width: 100%;;"><tr><td class="datatd">' + (isNull(c)? f : car(c)) + '</td></tr><tr><td class="datatd">...</td></tr></table>';
         return t;
     }
     if (wc == 'table') {
-        e.innerHTML = '<table class="datatable" style="width: 100%;"><tr><td class="datatdl">' + (isNil(c)? f : car(c)) + '</td><td class="datatdr">...</td></tr><tr><td class="datatdl">...</td><td class="datatdr">...</td></tr></table>';
+        e.innerHTML = '<table class="datatable" style="width: 100%;"><tr><td class="datatdl">' + (isNull(c)? f : car(c)) + '</td><td class="datatdr">...</td></tr><tr><td class="datatdl">...</td><td class="datatdr">...</td></tr></table>';
         return t;
     }
     if (wc == 'link') {
         var ce = car(childElements(e));
-        ce.href = isNil(c)? 'link:/index.html' : ('link:' + car(c));
-        car(childElements(ce)).innerHTML = isNil(c)? (f != ''? f : '/index.html') : isNil(cdr(c))? (f != ''? f : car(c)) : cadr(c);
+        ce.href = isNull(c)? 'link:/index.html' : ('link:' + car(c));
+        car(childElements(ce)).innerHTML = isNull(c)? (f != ''? f : '/index.html') : isNull(cdr(c))? (f != ''? f : car(c)) : cadr(c);
         return t;
     }
     if (wc == 'img') {
-        car(childElements(e)).src = isNil(c)? '/public/img.png' : car(c);
+        car(childElements(e)).src = isNull(c)? '/public/img.png' : car(c);
         return t;
     }
     return '';
@@ -512,7 +512,7 @@ function widgetbounds(e) {
     //debug('fixup br', e, br.left, br.top, br.right, br.bottom, t[0], t[1]);
     function fixuptransform(e) {
         var t = widgettransform(e);
-        if (!isNil(e.xtranslate))
+        if (!isNull(e.xtranslate))
             return [e.xtranslate, e.ytranslate];
         var t = e.style.getPropertyValue('-webkit-transform') || e.style.getPropertyValue('-moz-transform') ||
                 e.style.getPropertyValue('-ms-transform') || e.style.getPropertyValue('-o-transform') ||
@@ -538,12 +538,12 @@ function widgetbounds(e) {
  */
 function draggable(x, y, l) {
     //debug('draggable?', x, y, l);
-    if (isNil(l))
+    if (isNull(l))
         return null;
     var n = car(l);
-    if (isNil(n.id) || n.id == '') {
+    if (isNull(n.id) || n.id == '') {
         var d = draggable(x, y, reverse(nodeList(n.childNodes)));
-        if (!isNil(d))
+        if (!isNull(d))
             return d;
         return draggable(x, y, cdr(l));
     }
@@ -849,9 +849,9 @@ function mkeditor() {
         onpagechange(false);
 
         // On Firefox > 4, re-apply the outline after the widget has been repositioned
-        if (fffixupoutline && !isNil(selected)) {
+        if (fffixupoutline && !isNull(selected)) {
             ui.delay(function() {
-                if (!isNil(selected))
+                if (!isNull(selected))
                     selected.style.outline = '2px solid #598edd';
             }, 32);
         }
@@ -932,7 +932,7 @@ function mkeditor() {
             }
 
             // Dismiss the palette
-            if (palvis && isNil(draggable(moveX, moveY, mklist($('palettecontent')))))
+            if (palvis && isNull(draggable(moveX, moveY, mklist($('palettecontent')))))
                 hidepalette();
 
             return true;
@@ -1091,7 +1091,7 @@ function mkeditor() {
  * Get and display the requested app page.
  */
 (function getpage() {
-    if (isNil(appname))
+    if (isNull(appname))
         return false;
     workingstatus(true);
     showstatus('Loading');
@@ -1108,15 +1108,15 @@ function mkeditor() {
         // Get the page from the ATOM entry, convert it to XHTML and place it in a hidden buffer
         var pageentry = car(atom.readATOMEntry(mklist(doc)));
         var content = namedElementChild("'content", pageentry);
-        var el = isNil(content)? mklist() : elementChildren(content);
-        if (isNil(el))
+        var el = isNull(content)? mklist() : elementChildren(content);
+        if (isNull(el))
             $('xhtmlbuffer').innerHTML = '<div id="page"></div>';
         else
             $('xhtmlbuffer').innerHTML = writeStrings(writeXML(el, false));
 
         // Remove any existing page nodes from the editor div
         var fnodes = filter(function(e) {
-            if (isNil(e.id) || e.id == '')
+            if (isNull(e.id) || e.id == '')
                 return false;
             return true;
         }, nodeList($('pagediv').childNodes));
@@ -1169,7 +1169,7 @@ function pagexhtml() {
     // part of the page, as well as nodes positioned out the
     // editing area
     var fnodes = filter(function(e) {
-        if (isNil(e.id) || e.id == '')
+        if (isNull(e.id) || e.id == '')
             return false;
         return true;
     }, nodes);
diff --git a/sca-cpp/trunk/hosting/server/htdocs/proxy/public/oops/index.html b/sca-cpp/trunk/hosting/server/htdocs/proxy/public/oops/index.html
index 5ea9d7619d..f7cdab9bf2 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/proxy/public/oops/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/proxy/public/oops/index.html
@@ -161,7 +161,7 @@ try {
  * Initialize status message area.
  */
 (function initstatus() {
-    if (isNil($('status')))
+    if (isNull($('status')))
         return;
     $('status').style.display = 'none';
     
@@ -179,7 +179,7 @@ try {
  */
 window.showstatus = function(s, c) {
     //debug('show status', s);
-    if (isNil($('status')) || $('status').error)
+    if (isNull($('status')) || $('status').error)
         return s;
     $('status').innerHTML = '<span class="' + (c? c : 'okstatus') + '">' + s + '</span>';
     $('status').className = ui.isMobile()? 'status3dm' : 'status3d';
@@ -207,7 +207,7 @@ window.errorstatus = function(s) {
  */
 window.workingstatus = function(w, c) {
     //debug('show working', w);
-    if (isNil($('working')))
+    if (isNull($('working')))
         return w;
     if (!ui.isMobile())
         $('working').style.top = ui.pixpos(Math.round(window.clientHeight / 2));
@@ -329,7 +329,7 @@ var appresources = [
                     appcache.remove(res[0]);
                     appcache.get(res[0], 'remote');
                 }, append(appresources, config.appresources()));
-                if (!isNil(lcmf)) {
+                if (!isNull(lcmf)) {
                     //debug('reloading');
                     window.location.reload();
                 }
diff --git a/sca-cpp/trunk/hosting/server/htdocs/public/config.js b/sca-cpp/trunk/hosting/server/htdocs/public/config.js
index be23c7c01e..e3b966d542 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/public/config.js
+++ b/sca-cpp/trunk/hosting/server/htdocs/public/config.js
@@ -17,7 +17,7 @@
  * under the License.    
  */
 
-if (isNil(config))
+if (isNull(config))
     config = {};
 
 /**
diff --git a/sca-cpp/trunk/hosting/server/htdocs/public/notauth/index.html b/sca-cpp/trunk/hosting/server/htdocs/public/notauth/index.html
index f453e0491c..cf5f3465d8 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/public/notauth/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/public/notauth/index.html
@@ -161,7 +161,7 @@ try {
  * Initialize status message area.
  */
 (function initstatus() {
-    if (isNil($('status')))
+    if (isNull($('status')))
         return;
     $('status').style.display = 'none';
     
@@ -179,7 +179,7 @@ try {
  */
 window.showstatus = function(s, c) {
     //debug('show status', s);
-    if (isNil($('status')) || $('status').error)
+    if (isNull($('status')) || $('status').error)
         return s;
     $('status').innerHTML = '<span class="' + (c? c : 'okstatus') + '">' + s + '</span>';
     $('status').className = ui.isMobile()? 'status3dm' : 'status3d';
@@ -207,7 +207,7 @@ window.errorstatus = function(s) {
  */
 window.workingstatus = function(w, c) {
     //debug('show working', w);
-    if (isNil($('working')))
+    if (isNull($('working')))
         return w;
     if (!ui.isMobile())
         $('working').style.top = ui.pixpos(Math.round(window.clientHeight / 2));
@@ -328,7 +328,7 @@ var appresources = [
                     appcache.remove(res[0]);
                     appcache.get(res[0], 'remote');
                 }, append(appresources, config.appresources()));
-                if (!isNil(lcmf)) {
+                if (!isNull(lcmf)) {
                     //debug('reloading');
                     window.location.reload();
                 }
diff --git a/sca-cpp/trunk/hosting/server/htdocs/public/notfound/index.html b/sca-cpp/trunk/hosting/server/htdocs/public/notfound/index.html
index c8475147d7..ba82ecb897 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/public/notfound/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/public/notfound/index.html
@@ -162,7 +162,7 @@ try {
  * Initialize status message area.
  */
 (function initstatus() {
-    if (isNil($('status')))
+    if (isNull($('status')))
         return;
     $('status').style.display = 'none';
     
@@ -180,7 +180,7 @@ try {
  */
 window.showstatus = function(s, c) {
     //debug('show status', s);
-    if (isNil($('status')) || $('status').error)
+    if (isNull($('status')) || $('status').error)
         return s;
     $('status').innerHTML = '<span class="' + (c? c : 'okstatus') + '">' + s + '</span>';
     $('status').className = ui.isMobile()? 'status3dm' : 'status3d';
@@ -208,7 +208,7 @@ window.errorstatus = function(s) {
  */
 window.workingstatus = function(w, c) {
     //debug('show working', w);
-    if (isNil($('working')))
+    if (isNull($('working')))
         return w;
     if (!ui.isMobile())
         $('working').style.top = ui.pixpos(Math.round(window.clientHeight / 2));
@@ -329,7 +329,7 @@ var appresources = [
                     appcache.remove(res[0]);
                     appcache.get(res[0], 'remote');
                 }, append(appresources, config.appresources()));
-                if (!isNil(lcmf)) {
+                if (!isNull(lcmf)) {
                     //debug('reloading');
                     window.location.reload();
                 }
diff --git a/sca-cpp/trunk/hosting/server/htdocs/public/notyet/index.html b/sca-cpp/trunk/hosting/server/htdocs/public/notyet/index.html
index 4bcb3728ae..0597d10942 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/public/notyet/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/public/notyet/index.html
@@ -162,7 +162,7 @@ try {
  * Initialize status message area.
  */
 (function initstatus() {
-    if (isNil($('status')))
+    if (isNull($('status')))
         return;
     $('status').style.display = 'none';
     
@@ -180,7 +180,7 @@ try {
  */
 window.showstatus = function(s, c) {
     //debug('show status', s);
-    if (isNil($('status')) || $('status').error)
+    if (isNull($('status')) || $('status').error)
         return s;
     $('status').innerHTML = '<span class="' + (c? c : 'okstatus') + '">' + s + '</span>';
     $('status').className = ui.isMobile()? 'status3dm' : 'status3d';
@@ -208,7 +208,7 @@ window.errorstatus = function(s) {
  */
 window.workingstatus = function(w, c) {
     //debug('show working', w);
-    if (isNil($('working')))
+    if (isNull($('working')))
         return w;
     if (!ui.isMobile())
         $('working').style.top = ui.pixpos(Math.round(window.clientHeight / 2));
@@ -329,7 +329,7 @@ var appresources = [
                     appcache.remove(res[0]);
                     appcache.get(res[0], 'remote');
                 }, append(appresources, config.appresources()));
-                if (!isNil(lcmf)) {
+                if (!isNull(lcmf)) {
                     //debug('reloading');
                     window.location.reload();
                 }
diff --git a/sca-cpp/trunk/hosting/server/htdocs/public/oops/index.html b/sca-cpp/trunk/hosting/server/htdocs/public/oops/index.html
index 68554efdb0..788435289f 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/public/oops/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/public/oops/index.html
@@ -161,7 +161,7 @@ try {
  * Initialize status message area.
  */
 (function initstatus() {
-    if (isNil($('status')))
+    if (isNull($('status')))
         return;
     $('status').style.display = 'none';
     
@@ -179,7 +179,7 @@ try {
  */
 window.showstatus = function(s, c) {
     //debug('show status', s);
-    if (isNil($('status')) || $('status').error)
+    if (isNull($('status')) || $('status').error)
         return s;
     $('status').innerHTML = '<span class="' + (c? c : 'okstatus') + '">' + s + '</span>';
     $('status').className = ui.isMobile()? 'status3dm' : 'status3d';
@@ -207,7 +207,7 @@ window.errorstatus = function(s) {
  */
 window.workingstatus = function(w, c) {
     //debug('show working', w);
-    if (isNil($('working')))
+    if (isNull($('working')))
         return w;
     if (!ui.isMobile())
         $('working').style.top = ui.pixpos(Math.round(window.clientHeight / 2));
@@ -328,7 +328,7 @@ var appresources = [
                     appcache.remove(res[0]);
                     appcache.get(res[0], 'remote');
                 }, append(appresources, config.appresources()));
-                if (!isNil(lcmf)) {
+                if (!isNull(lcmf)) {
                     //debug('reloading');
                     window.location.reload();
                 }
diff --git a/sca-cpp/trunk/hosting/server/htdocs/rate/index.html b/sca-cpp/trunk/hosting/server/htdocs/rate/index.html
index 22f11f631a..90d45bd3ea 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/rate/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/rate/index.html
@@ -116,7 +116,7 @@ var savedxml = '';
  * Get and display the requested app rating.
  */
 (function getrating() {
-    if (isNil(appname))
+    if (isNull(appname))
         return false;
     workingstatus(true);
     showstatus('Loading');
@@ -133,7 +133,7 @@ var savedxml = '';
         appentry = doc != null? car(elementsToValues(atom.readATOMEntry(mklist(doc)))) : mklist("'entry", mklist("'title", ''), mklist("'id", appname));
         savedxml = car(atom.writeATOMEntry(valuesToElements(mklist(appentry))));
         var content = cadr(assoc("'content", appentry));
-        if (!isNil(content))
+        if (!isNull(content))
             selectrating(parseInt(cadr(content)));
 
         onlinestatus();
diff --git a/sca-cpp/trunk/hosting/server/htdocs/search/index.html b/sca-cpp/trunk/hosting/server/htdocs/search/index.html
index 47d5a757f3..d46b0528c4 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/search/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/search/index.html
@@ -74,7 +74,7 @@ function viewapp(appname) {
  * Get and display an app icon.
  */
 function geticon(appname) {
-    if (isNil(appname))
+    if (isNull(appname))
         return false;
 
     return icons.get(appname, function(doc) {
@@ -86,9 +86,9 @@ function geticon(appname) {
         var content = assoc("'content", iconentry);
         var icon = assoc("'icon", content);
         var img = assoc("'image", icon);
-        if (!isNil(img)) {
+        if (!isNull(img)) {
             var appimg = $('search_app_img_' + appname);
-            if (!isNil(appimg))
+            if (!isNull(appimg))
                 appimg.src = cadr(img);
         }
         return true;
@@ -114,7 +114,7 @@ function getapps(query) {
 
         var feed = car(elementsToValues(atom.readATOMFeed(mklist(doc))));
         var aentries = assoc("'entry", feed);
-        var entries = isNil(aentries)? mklist() : isList(car(cadr(aentries)))? cadr(aentries) : mklist(cdr(aentries));
+        var entries = isNull(aentries)? mklist() : isList(car(cadr(aentries)))? cadr(aentries) : mklist(cdr(aentries));
 
         var defappimg = ui.b64png(appcache.get('/public/app.b64'));
 
@@ -122,7 +122,7 @@ function getapps(query) {
         var icons = mklist();
 
         (function displayentries(entries) {
-            if (isNil(entries))
+            if (isNull(entries))
                 return apps;
             var entry = car(entries);
             var title = cadr(assoc("'title", entry))
@@ -136,8 +136,8 @@ function getapps(query) {
             var ar2 = assoc("'rating2", aratings);
             var ar3 = assoc("'rating3", aratings);
             var ar4 = assoc("'rating4", aratings);
-            var rating = isNil(ar)? 0 : Number(cadr(ar));
-            var reviews = (isNil(ar1)? 0 : Number(cadr(ar1))) + (isNil(ar2)? 0 : Number(cadr(ar2))) + (isNil(ar3)? 0 : Number(cadr(ar3))) + (isNil(ar4)? 0 : Number(cadr(ar4)));
+            var rating = isNull(ar)? 0 : Number(cadr(ar));
+            var reviews = (isNull(ar1)? 0 : Number(cadr(ar1))) + (isNull(ar2)? 0 : Number(cadr(ar2))) + (isNull(ar3)? 0 : Number(cadr(ar3))) + (isNull(ar4)? 0 : Number(cadr(ar4)));
 
             apps += '<div class="box">'
             apps += '<div class="appicon">'
@@ -165,7 +165,7 @@ function getapps(query) {
         ui.unmemo$('search_app_');
 
         (function displayicons(icons) {
-            if (isNil(icons))
+            if (isNull(icons))
                 return true;
             geticon(car(icons));
             return displayicons(cdr(icons));
diff --git a/sca-cpp/trunk/hosting/server/htdocs/store/index.html b/sca-cpp/trunk/hosting/server/htdocs/store/index.html
index 15e7aeed0c..57920ede2e 100644
--- a/sca-cpp/trunk/hosting/server/htdocs/store/index.html
+++ b/sca-cpp/trunk/hosting/server/htdocs/store/index.html
@@ -59,10 +59,10 @@ var categories = [
  * Find a store category.
  */
 function findcategory(name) {
-    if (isNil(name))
+    if (isNull(name))
         return findcategory('featured');
     var f = filter(function(c) { return cadr(c) == name }, categories);
-    if (isNil(f))
+    if (isNull(f))
         return findcategory('featured');
     return car(f);
 }
@@ -121,7 +121,7 @@ $('createApp').onclick = function() {
  * Get and display an app icon.
  */
 function geticon(appname) {
-    if (isNil(appname))
+    if (isNull(appname))
         return false;
 
     return icons.get(appname, function(doc) {
@@ -133,9 +133,9 @@ function geticon(appname) {
         var content = assoc("'content", iconentry);
         var icon = assoc("'icon", content);
         var img = assoc("'image", icon);
-        if (!isNil(img)) {
+        if (!isNull(img)) {
             var appimg = $('store_app_img_' + appname);
-            if (!isNil(appimg))
+            if (!isNull(appimg))
                 appimg.src = cadr(img);
         }
         return true;
@@ -161,7 +161,7 @@ function geticon(appname) {
 
         var feed = car(elementsToValues(atom.readATOMFeed(mklist(doc))));
         var aentries = assoc("'entry", feed);
-        var entries = isNil(aentries)? mklist() : isList(car(cadr(aentries)))? cadr(aentries) : mklist(cdr(aentries));
+        var entries = isNull(aentries)? mklist() : isList(car(cadr(aentries)))? cadr(aentries) : mklist(cdr(aentries));
 
         var defappimg = ui.b64png(appcache.get('/public/app.b64'));
 
@@ -169,7 +169,7 @@ function geticon(appname) {
         var icons = mklist();
 
         (function displayentries(entries) {
-            if (isNil(entries))
+            if (isNull(entries))
                 return apps;
             var entry = car(entries);
             var title = cadr(assoc("'title", entry))
@@ -183,8 +183,8 @@ function geticon(appname) {
             var ar2 = assoc("'rating2", aratings);
             var ar3 = assoc("'rating3", aratings);
             var ar4 = assoc("'rating4", aratings);
-            var rating = isNil(ar)? 0 : Number(cadr(ar));
-            var reviews = (isNil(ar1)? 0 : Number(cadr(ar1))) + (isNil(ar2)? 0 : Number(cadr(ar2))) + (isNil(ar3)? 0 : Number(cadr(ar3))) + (isNil(ar4)? 0 : Number(cadr(ar4)));
+            var rating = isNull(ar)? 0 : Number(cadr(ar));
+            var reviews = (isNull(ar1)? 0 : Number(cadr(ar1))) + (isNull(ar2)? 0 : Number(cadr(ar2))) + (isNull(ar3)? 0 : Number(cadr(ar3))) + (isNull(ar4)? 0 : Number(cadr(ar4)));
 
             apps += '<div class="box">'
             apps += '<div class="appicon">'
@@ -213,7 +213,7 @@ function geticon(appname) {
         ui.unmemo$('store_app_');
 
         (function displayicons(icons) {
-            if (isNil(icons))
+            if (isNull(icons))
                 return true;
             geticon(car(icons));
             return displayicons(cdr(icons));
diff --git a/sca-cpp/trunk/hosting/server/icons.py b/sca-cpp/trunk/hosting/server/icons.py
index 7ee9ae9bfb..d9fbcab448 100644
--- a/sca-cpp/trunk/hosting/server/icons.py
+++ b/sca-cpp/trunk/hosting/server/icons.py
@@ -49,7 +49,7 @@ def put(id, icon, user, cache, apps):
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('icons.py::put', 'app not found', id)
         return False
 
@@ -61,23 +61,23 @@ def put(id, icon, user, cache, apps):
     # Get image and token from input icon
     def image(c):
         img = assoc("'image", c)
-        return None if isNil(img) else to50x50png(cadr(img))
+        return None if isNull(img) else to50x50png(cadr(img))
     def token(c):
         tok = assoc("'token", c)
-        return None if isNil(tok) else cadr(tok)
+        return None if isNull(tok) else cadr(tok)
     img = image(content(icon))
     tok = token(content(icon))
 
     # Update the icon
     # Put with an upload token
-    if not isNil(tok):
+    if not isNull(tok):
         debug('icons.py::put::token', tok)
 
         # Token alone, store token with existing image, if any
-        if isNil(img):
+        if isNull(img):
             eicon = cache.get(iconid(id))
-            eimg = None if isNil(eicon) else image(content(eicon))
-            if isNil(eimg):
+            eimg = None if isNull(eicon) else image(content(eicon))
+            if isNull(eimg):
                 iconentry = mkentry(title(app), car(id), author(app), now(), ("'icon", ("'token", tok)))
                 debug('icons.py::put::iconentry', iconentry)
                 return cache.put(iconid(id), iconentry)
@@ -90,9 +90,9 @@ def put(id, icon, user, cache, apps):
         # Token plus image, put image if token is valid, removing the token
         debug('icons.py::put::img', img)
         eicon = cache.get(iconid(id))
-        etok = None if isNil(eicon) else token(content(eicon))
+        etok = None if isNull(eicon) else token(content(eicon))
         debug('icons.py::put::etok', etok)
-        if isNil(etok) or tok != etok:
+        if isNull(etok) or tok != etok:
             debug('icons.py::put', 'invalid token', tok)
             return False
 
@@ -101,7 +101,7 @@ def put(id, icon, user, cache, apps):
         return cache.put(iconid(id), iconentry)
 
     # Update icon image
-    if not isNil(img):
+    if not isNull(img):
         debug('icons.py::put::img', img)
         iconentry = mkentry(title(app), car(id), author(app), now(), ("'icon", ("'image", img)))
         debug('icons.py::put::iconentry', iconentry)
@@ -115,12 +115,12 @@ def put(id, icon, user, cache, apps):
 # Get an icon
 def get(id, user, cache, apps):
     debug('icons.py::get::id', id)
-    if isNil(id):
+    if isNull(id):
         return (("'feed", ("'title", "Icons"), ("'id", "icons")),)
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('icons.py::get', 'app not found', id)
 
         # Return a default new icon
@@ -128,7 +128,7 @@ def get(id, user, cache, apps):
 
     # Get the requested icon
     icon = cache.get(iconid(id))
-    if isNil(icon):
+    if isNull(icon):
         debug('icons.py::get', 'icon not found', id)
 
         # Return a default new icon
@@ -137,16 +137,16 @@ def get(id, user, cache, apps):
     # Get image, token, and updated date from icon
     def image(c):
         img = assoc("'image", c)
-        return None if isNil(img) else cadr(img)
+        return None if isNull(img) else cadr(img)
     def token(c):
         tok = assoc("'token", c)
-        return None if isNil(tok) else cadr(tok)
+        return None if isNull(tok) else cadr(tok)
     img = image(content(icon))
     tok = token(content(icon))
 
     # Return the icon
-    iconc = (() if isNil(img) else (("'image", img),)) + (() if isNil(tok) or (user.get(()) != author(app) and user.get(()) != 'admin') else (("'token", tok),))
-    if isNil(iconc):
+    iconc = (() if isNull(img) else (("'image", img),)) + (() if isNull(tok) or (user.get(()) != author(app) and user.get(()) != 'admin') else (("'token", tok),))
+    if isNull(iconc):
         iconentry = mkentry(title(app), car(id), author(app), updated(icon), ())
         debug('icons.py::get::iconentry', iconentry)
         return iconentry
@@ -161,7 +161,7 @@ def delete(id, user, cache, apps):
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('icons.py::delete', 'app not found', id)
         return False
 
diff --git a/sca-cpp/trunk/hosting/server/pages.py b/sca-cpp/trunk/hosting/server/pages.py
index d8c774c14d..3d353279ba 100644
--- a/sca-cpp/trunk/hosting/server/pages.py
+++ b/sca-cpp/trunk/hosting/server/pages.py
@@ -31,7 +31,7 @@ def put(id, page, user, cache, apps):
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('pages.py::put', 'app not found', id)
         return False
 
@@ -48,12 +48,12 @@ def put(id, page, user, cache, apps):
 # Get a page from the page db
 def get(id, user, cache, apps):
     debug('pages.py::get::id', id)
-    if isNil(id):
+    if isNull(id):
         return (("'feed", ("'title", "Pages"), ("'id", "pages")),)
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('pages.py::get', 'app not found', id)
 
         # Return a default new page
@@ -61,7 +61,7 @@ def get(id, user, cache, apps):
 
     # Get the requested page
     page = cache.get(pageid(id))
-    if isNil(page):
+    if isNull(page):
         debug('pages.py::get', 'page not found', id)
 
         # Return a default new page
@@ -80,7 +80,7 @@ def delete(id, user, cache, apps):
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('pages.py::delete', 'app not found', id)
         return False
 
diff --git a/sca-cpp/trunk/hosting/server/palettes.py b/sca-cpp/trunk/hosting/server/palettes.py
index 38e012835a..be681f874c 100644
--- a/sca-cpp/trunk/hosting/server/palettes.py
+++ b/sca-cpp/trunk/hosting/server/palettes.py
@@ -30,7 +30,7 @@ def put(id, palette, cache):
 
 # Get a palette from the palettes db
 def get(id, cache):
-    if isNil(id):
+    if isNull(id):
         return (("'feed", ("'title", "Palettes"), ("'id", "palettes")),)
     return mkentry(car(id), car(id), None, now(), car(cache.get(paletteid(id))))
 
diff --git a/sca-cpp/trunk/hosting/server/pictures.py b/sca-cpp/trunk/hosting/server/pictures.py
index fab7df47ce..6c5e268e0f 100644
--- a/sca-cpp/trunk/hosting/server/pictures.py
+++ b/sca-cpp/trunk/hosting/server/pictures.py
@@ -47,7 +47,7 @@ def put(id, picture, user, cache):
     debug('pictures.py::put::id', id)
     debug('pictures.py::put::picture', picture)
 
-    picid = user.get(()) if isNil(id) else car(id)
+    picid = user.get(()) if isNull(id) else car(id)
 
     # Only the admin can update other user's pictures
     if picid != user.get(()) and user.get(()) != 'admin':
@@ -57,23 +57,23 @@ def put(id, picture, user, cache):
     # Get image and token from input picture
     def image(c):
         img = assoc("'image", c)
-        return None if isNil(img) else to50x50png(cadr(img))
+        return None if isNull(img) else to50x50png(cadr(img))
     def token(c):
         tok = assoc("'token", c)
-        return None if isNil(tok) else cadr(tok)
+        return None if isNull(tok) else cadr(tok)
     img = image(content(picture))
     tok = token(content(picture))
 
     # Update the picture
     # Put with an upload token
-    if not isNil(tok):
+    if not isNull(tok):
         debug('pictures.py::put::token', tok)
 
         # Token alone, store token with existing image, if any
-        if isNil(img):
+        if isNull(img):
             epicture = cache.get(pictureid(picid))
-            eimg = None if isNil(epicture) else image(content(epicture))
-            if isNil(eimg):
+            eimg = None if isNull(epicture) else image(content(epicture))
+            if isNull(eimg):
                 picentry = mkentry(title(picture), picid, picid, now(), ("'picture", ("'token", tok)))
                 debug('pictures.py::put::picentry', picentry)
                 return cache.put(pictureid(picid), picentry)
@@ -86,9 +86,9 @@ def put(id, picture, user, cache):
         # Token plus image, put image if token is valid, removing the token
         debug('pictures.py::put::img', img)
         epicture = cache.get(pictureid(picid))
-        etok = None if isNil(epicture) else token(content(epicture))
+        etok = None if isNull(epicture) else token(content(epicture))
         debug('pictures.py::put::etok', etok)
-        if isNil(etok) or tok != etok:
+        if isNull(etok) or tok != etok:
             debug('pictures.py::put', 'invalid token', tok)
             return False
 
@@ -97,7 +97,7 @@ def put(id, picture, user, cache):
         return cache.put(pictureid(picid), picentry)
 
     # Update picture image
-    if not isNil(img):
+    if not isNull(img):
         debug('pictures.py::put::img', img)
         picentry = mkentry(title(picture), picid, picid, now(), ("'picture", ("'image", img)))
         debug('pictures.py::put::picentry', picentry)
@@ -113,24 +113,24 @@ def get(id, user, cache):
     debug('pictures.py::get::id', id)
 
     # Get the requested picture
-    picid = user.get(()) if isNil(id) else car(id)
+    picid = user.get(()) if isNull(id) else car(id)
     picture = cache.get(pictureid(picid))
-    if isNil(picture):
+    if isNull(picture):
         return mkentry(picid, picid, picid, now(), ())
 
     # Get image and token from picture
     def image(c):
         img = assoc("'image", c)
-        return None if isNil(img) else cadr(img)
+        return None if isNull(img) else cadr(img)
     def token(c):
         tok = assoc("'token", c)
-        return None if isNil(tok) else cadr(tok)
+        return None if isNull(tok) else cadr(tok)
     img = image(content(picture))
     tok = token(content(picture))
 
     # Return the picture
-    picc = (() if isNil(img) else (("'image", img),)) + (() if isNil(tok) or (user.get(()) != author(picture) and user.get(()) != 'admin') else (("'token", tok),))
-    if isNil(picc):
+    picc = (() if isNull(img) else (("'image", img),)) + (() if isNull(tok) or (user.get(()) != author(picture) and user.get(()) != 'admin') else (("'token", tok),))
+    if isNull(picc):
         picentry = mkentry(title(picture), picid, author(picture), updated(picture), ())
         debug('pictures.py::get::picentry', picentry)
         return picentry
diff --git a/sca-cpp/trunk/hosting/server/ratings.py b/sca-cpp/trunk/hosting/server/ratings.py
index 5638d8609f..d36dcad45e 100644
--- a/sca-cpp/trunk/hosting/server/ratings.py
+++ b/sca-cpp/trunk/hosting/server/ratings.py
@@ -31,7 +31,7 @@ def put(id, ratings, user, cache, db, apps):
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('ratings.py::put', 'app not found', id)
         return False
 
@@ -52,7 +52,7 @@ def patch(id, ratings, user, cache, db, apps):
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('ratings.py::patch', 'app not found', id)
         return False
 
@@ -107,9 +107,9 @@ def get(id, user, cache, db, apps):
     debug('ratings.py::get::id', id)
 
     # Return the top ratings
-    if isNil(id):
+    if isNull(id):
         topentries = db.get((("'regex", '("ratings" .* "app.ratings")'), ("'rank", "(regexp_matches(value, '(.*\(rating )([^\)]+)(\).*)'))[2]::float"), ("'limit", 25)))
-        flatentries = tuple(map(lambda v: car(v), () if isNil(topentries) else topentries))
+        flatentries = tuple(map(lambda v: car(v), () if isNull(topentries) else topentries))
         def rating(e):
             return cadr(assoc("'rating", assoc("'ratings", assoc("'content", e))))
         sortedentries = tuple(sorted(flatentries, key = rating, reverse = True))
@@ -119,7 +119,7 @@ def get(id, user, cache, db, apps):
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('ratings.py::get', 'app not found', id)
 
         # Return default ratings
@@ -127,7 +127,7 @@ def get(id, user, cache, db, apps):
 
     # Get the requested ratings
     ratings = cache.get(ratingsid(id))
-    if isNil(ratings):
+    if isNull(ratings):
         debug('ratings.py::get', 'ratings not found', id)
 
         # Return default ratings
@@ -144,7 +144,7 @@ def delete(id, user, cache, db, apps):
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('ratings.py::delete', 'app not found', id)
         return False
 
diff --git a/sca-cpp/trunk/hosting/server/reviews.py b/sca-cpp/trunk/hosting/server/reviews.py
index 3c175d8a0f..f3c610467e 100644
--- a/sca-cpp/trunk/hosting/server/reviews.py
+++ b/sca-cpp/trunk/hosting/server/reviews.py
@@ -28,10 +28,10 @@ def reviewsid(user):
 def getreviews(id, cache):
     debug('reviews.py::getreviews::id', id)
     val = cache.get(id)
-    if isNil(val):
+    if isNull(val):
         return ()
     reviews = cdddr(car(val))
-    if not isNil(reviews) and isList(car(cadr(car(reviews)))):
+    if not isNull(reviews) and isList(car(cadr(car(reviews)))):
         # Expand list of entries
         ereviews = tuple(map(lambda e: cons("'entry", e), cadr(car(reviews))))
         debug('reviews.py::getreviews::ereviews', ereviews)
@@ -42,7 +42,7 @@ def getreviews(id, cache):
 
 # Get a review from a user's reviews
 def getreview(id, reviews):
-    if isNil(reviews):
+    if isNull(reviews):
         return None
     if car(id) == entryid(reviews):
         return (car(reviews),)
@@ -51,20 +51,20 @@ def getreview(id, reviews):
 # Get reviews from the user's reviews
 def get(id, user, cache, apps, ratings):
     debug('reviews.py::get::id', id)
-    if isNil(id):
+    if isNull(id):
         reviews = ((("'feed", ("'title", "Your Reviews"), ("'id", user.get(()))) + getreviews(reviewsid(user), cache)),)
         debug('reviews.py::get::reviews', reviews)
         return reviews
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('reviews.py::get', 'app not found', id)
         return False
 
     # Get the review
     review = getreview(id, getreviews(reviewsid(user), cache))
-    if isNil(review):
+    if isNull(review):
         debug('reviews.py::get', 'review not found', id)
 
         # Return a default empty review
@@ -75,7 +75,7 @@ def get(id, user, cache, apps, ratings):
 
 # Patch an app ratings
 def patchratings(id, user, ratings, oreview, nreview):
-    patch = ("'patch", ("'old", "0" if isNil(oreview) else cadr(content(oreview))), ("'new", "0" if isNil(nreview) else cadr(content(nreview))))
+    patch = ("'patch", ("'old", "0" if isNull(oreview) else cadr(content(oreview))), ("'new", "0" if isNull(nreview) else cadr(content(nreview))))
     patchentry = mkentry(car(id), car(id), user.get(()), now(), patch);
     debug('reviews.py::patchratings::patchentry', patchentry)
     return ratings.patch(id, patchentry)
@@ -89,7 +89,7 @@ def putreviews(id, reviews, cache):
 
 # Put a review into a user's reviews
 def putreview(id, review, reviews):
-    if isNil(reviews):
+    if isNull(reviews):
         return review
     if car(id) == entryid(reviews):
         return cons(car(review), cdr(reviews))
@@ -102,7 +102,7 @@ def put(id, review, user, cache, apps, ratings):
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('reviews.py::put', 'app not found', id)
         return False
 
@@ -122,7 +122,7 @@ def put(id, review, user, cache, apps, ratings):
 
 # Delete a review from a reviews record
 def deletereview(id, reviews):
-    if isNil(reviews):
+    if isNull(reviews):
         return ()
     if car(id) == entryid(reviews):
         return cdr(reviews)
@@ -131,19 +131,19 @@ def deletereview(id, reviews):
 # Delete reviews from the user's reviews record
 def delete(id, user, cache, apps, ratings):
     debug('reviews.py::delete::id', id)
-    if isNil(id):
+    if isNull(id):
         return cache.delete(reviewsid(user))
 
     # Get the requested app
     app = apps.get(id)
-    if isNil(app):
+    if isNull(app):
         debug('reviews.py::delete', 'app not found', id)
         return False
 
     # Get the review
     reviews = getreviews(reviewsid(user), cache)
     review = getreview(id, reviews)
-    if isNil(review):
+    if isNull(review):
         debug('reviews.py::delete', 'review not found', id)
         return False
 
diff --git a/sca-cpp/trunk/hosting/server/search.py b/sca-cpp/trunk/hosting/server/search.py
index b1a7d36733..e79ff0ce51 100644
--- a/sca-cpp/trunk/hosting/server/search.py
+++ b/sca-cpp/trunk/hosting/server/search.py
@@ -30,10 +30,10 @@ def mergeratings(entries, ratings):
         info = content(app)
         rating = ratings.get(id)
         rates = content(rating)
-        mergedentry = mkentry(title(app), car(id), author(app), updated(app), ("'info",) + (() if isNil(info) else cdr(info)) + (() if isNil(rates) else cdr(rates)))
+        mergedentry = mkentry(title(app), car(id), author(app), updated(app), ("'info",) + (() if isNull(info) else cdr(info)) + (() if isNull(rates) else cdr(rates)))
         return mergedentry
 
-    mergedentries = tuple(filter(lambda e: not isNil(e), map(lambda e: car(mergerating((e,))), entries)))
+    mergedentries = tuple(filter(lambda e: not isNull(e), map(lambda e: car(mergerating((e,))), entries)))
     debug('search.py::mergeratings::mergedentries', mergedentries)
     return mergedentries
 
@@ -41,7 +41,7 @@ def mergeratings(entries, ratings):
 def get(id, user, cache, db, apps, ratings):
     debug('search.py::get::id', id)
     q = assoc("'q", id)
-    if isNil(q):
+    if isNull(q):
         return None
 
     # Run the search
@@ -49,7 +49,7 @@ def get(id, user, cache, db, apps, ratings):
     debug('search.py::get::foundentries', foundentries)
 
     # Merge app ratings
-    appentries = mergeratings(tuple(map(lambda v: car(v), () if isNil(foundentries) else foundentries)), ratings)
+    appentries = mergeratings(tuple(map(lambda v: car(v), () if isNull(foundentries) else foundentries)), ratings)
 
     results = ((("'feed", ("'title", "Search Results"), ("'id", 'search')) + appentries),)
     debug('search.py::get::results', results)
diff --git a/sca-cpp/trunk/hosting/server/selector.py b/sca-cpp/trunk/hosting/server/selector.py
index 33cd9512cc..4cbe31ba37 100644
--- a/sca-cpp/trunk/hosting/server/selector.py
+++ b/sca-cpp/trunk/hosting/server/selector.py
@@ -20,9 +20,9 @@ from util import *
 
 # Get the database to use for a particular key
 def get(id, db):
-    if isNil(id):
+    if isNull(id):
         return db
-    if not isNil(filter(lambda i: isList(i) and not isNil(i) and car(i) == "'limit", id)):
+    if not isNull(filter(lambda i: isList(i) and not isNull(i) and car(i) == "'limit", id)):
         return db
     if cadr(id)[0:1].lower() < 'm':
         return (db[0],)
diff --git a/sca-cpp/trunk/hosting/server/store.py b/sca-cpp/trunk/hosting/server/store.py
index 058505b4ee..aac233f877 100644
--- a/sca-cpp/trunk/hosting/server/store.py
+++ b/sca-cpp/trunk/hosting/server/store.py
@@ -30,10 +30,10 @@ def getstore(id, cache):
 
     # Lookup the requested store
     val = cache.get(id)
-    if isNil(val):
+    if isNull(val):
         return ()
     store = cdddr(car(val))
-    if not isNil(store) and isList(car(cadr(car(store)))):
+    if not isNull(store) and isList(car(cadr(car(store)))):
         # Expand list of entries
         estore = tuple(map(lambda e: cons("'entry", e), cadr(car(store))))
         debug('store.py::getstore::estore', estore)
@@ -57,7 +57,7 @@ def put(id, app, user, cache, apps, ratings):
     appid = cdr(id)
 
     def putapp(appid, app, store):
-        if isNil(store):
+        if isNull(store):
             return app
         if car(appid) == entryid(store):
             return cons(car(app), cdr(store))
@@ -77,15 +77,15 @@ def mergeapps(entries, apps, ratings):
         debug('store.py::mergeapp::entry', entry)
         id = (entryid(entry),)
         app = apps.get(id)
-        if isNil(app):
+        if isNull(app):
             return ((),)
         info = content(app)
         rating = ratings.get(id)
         rates = content(rating)
-        mergedentry = mkentry(title(app), car(id), author(app), updated(app), ("'info",) + (() if isNil(info) else cdr(info)) + (() if isNil(rates) else cdr(rates)))
+        mergedentry = mkentry(title(app), car(id), author(app), updated(app), ("'info",) + (() if isNull(info) else cdr(info)) + (() if isNull(rates) else cdr(rates)))
         return mergedentry
 
-    mergedentries = tuple(filter(lambda e: not isNil(e), map(lambda e: car(mergeapp((e,))), entries)))
+    mergedentries = tuple(filter(lambda e: not isNull(e), map(lambda e: car(mergeapp((e,))), entries)))
     debug('store.py::mergeapps::mergedentries', mergedentries)
     return mergedentries
 
@@ -105,13 +105,13 @@ def get(id, user, cache, apps, ratings):
     # Collect the featured apps
     appid = cdr(id)
     def findapp(appid, store):
-        if isNil(store):
+        if isNull(store):
             return None
         if car(appid) == entryid(store):
             return (car(store),)
         return findapp(appid, cdr(store))
 
-    if isNil(appid):
+    if isNull(appid):
         storeapps = mergeapps(getstore(storeid(tag), cache), apps, ratings)
         store = ((("'feed", ("'title", "App Store"), ("'id", tag)) + storeapps),)
         debug('store.py::get::store', store)
@@ -127,11 +127,11 @@ def delete(id, user, cache, apps, ratings):
     tag = car(id)
     appid = cdr(id)
 
-    if isNil(appid):
+    if isNull(appid):
         return cache.delete(storeid(tag))
 
     def deleteapp(appid, store):
-        if isNil(store):
+        if isNull(store):
             return ()
         if car(appid) == entryid(store):
             return cdr(store)
diff --git a/sca-cpp/trunk/hosting/server/util.py b/sca-cpp/trunk/hosting/server/util.py
index 791951a71c..bd37eb11af 100644
--- a/sca-cpp/trunk/hosting/server/util.py
+++ b/sca-cpp/trunk/hosting/server/util.py
@@ -57,9 +57,9 @@ def reverse(l):
     r.reverse()
     return tuple(r)
 
-def isNil(l):
+def isNull(l):
     if isinstance(l, streampair):
-        return l.isNil()
+        return l.isNull()
     return l is None or l == ()
 
 def isSymbol(v):
@@ -76,7 +76,7 @@ def isList(v):
     return True
 
 def isTaggedList(v, t):
-    return isList(v) and not isNil(v) and car(v) == t
+    return isList(v) and not isNull(v) and car(v) == t
 
 
 # Scheme-like streams
@@ -88,7 +88,7 @@ class streampair(object):
     def __repr__(self):
         return repr(self[0:len(self)])
 
-    def isNil(self):
+    def isNull(self):
         return self.cdr == ()
 
     def __len__(self):
@@ -102,7 +102,7 @@ class streampair(object):
         return self.cdr()[i - 1]
 
     def __getslice__(self, i, j):
-        if isNil(self):
+        if isNull(self):
             return ()
         if i > 0:
             if j == maxint:
@@ -156,7 +156,7 @@ def curry(f, *args):
 
 # Convert a path represented as a list of values to a string
 def path(p):
-    if isNil(p):
+    if isNull(p):
         return ""
     return "/" + car(p) + path(cdr(p))
 
diff --git a/sca-cpp/trunk/kernel/element.hpp b/sca-cpp/trunk/kernel/element.hpp
index d8907c8d21..4798570982 100644
--- a/sca-cpp/trunk/kernel/element.hpp
+++ b/sca-cpp/trunk/kernel/element.hpp
@@ -43,7 +43,7 @@ const string atsign("@");
  * Returns true if a value is an element.
  */
 inline const bool isElement(const value& v) {
-    if (!isList(v) || isNil(v) || element != car<value>(v))
+    if (!isList(v) || isNull(v) || element != car<value>(v))
         return false;
     return true;
 }
@@ -52,7 +52,7 @@ inline const bool isElement(const value& v) {
  * Returns true if a value is an attribute.
  */
 inline const bool isAttribute(const value& v) {
-    if (!isList(v) || isNil(v) || attribute != car<value>(v))
+    if (!isList(v) || isNull(v) || attribute != car<value>(v))
         return false;
     return true;
 }
@@ -82,7 +82,7 @@ inline const value elementName(const list<value>& l) {
  * Returns true if an element has children.
  */
 inline const bool elementHasChildren(const list<value>& l) {
-    return !isNil(cddr(l));
+    return !isNull(cddr(l));
 }
 
 /**
@@ -99,7 +99,7 @@ inline const bool elementHasValue(const list<value>& l) {
     const list<value> r = reverse(l);
     if (isSymbol(car(r)))
         return false;
-    if(isList(car(r)) && !isNil((list<value>)car(r)) && isSymbol(car<value>(car(r))))
+    if(isList(car(r)) && !isNull((list<value>)car(r)) && isSymbol(car<value>(car(r))))
         return false;
     return true;
 }
@@ -118,7 +118,7 @@ inline const bool elementToValueIsList(const value& v) {
     if (!isList(v))
         return false;
     const list<value> l = v;
-    return (isNil(l) || !isSymbol(car(l)));
+    return (isNull(l) || !isSymbol(car(l)));
 }
 
 inline const value elementToValue(const value& t) {
@@ -159,7 +159,7 @@ inline const bool elementToValueIsSymbol(const value& v) {
     if (!isList(v))
         return false;
     const list<value> l = v;
-    if (isNil(l))
+    if (isNull(l))
         return false;
     if (!isSymbol(car(l)))
         return false;
@@ -167,7 +167,7 @@ inline const bool elementToValueIsSymbol(const value& v) {
 }
 
 inline const list<value> elementToValueGroupValues(const value& v, const list<value>& l) {
-    if (isNil(l) || !elementToValueIsSymbol(v) || !elementToValueIsSymbol(car(l)))
+    if (isNull(l) || !elementToValueIsSymbol(v) || !elementToValueIsSymbol(car(l)))
         return cons(v, l);
     if (car<value>(car(l)) != car<value>(v))
         return cons(v, l);
@@ -181,7 +181,7 @@ inline const list<value> elementToValueGroupValues(const value& v, const list<va
 }
 
 inline const list<value> elementsToValues(const list<value>& e) {
-    if (isNil(e))
+    if (isNull(e))
         return e;
     return elementToValueGroupValues(elementToValue(car(e)), elementsToValues(cdr(e)));
 }
@@ -193,9 +193,9 @@ inline const value valueToElement(const value& t) {
     const list<value> valuesToElements(const list<value>& l);
 
     // Convert a name value pair
-    if (isList(t) && !isNil((list<value>)t) && isSymbol(car<value>(t))) {
+    if (isList(t) && !isNull((list<value>)t) && isSymbol(car<value>(t))) {
         const value n = car<value>(t);
-        const value v = isNil(cdr<value>(t))? nilValue : cadr<value>(t);
+        const value v = isNull(cdr<value>(t))? nilValue : cadr<value>(t);
 
         // Convert a single value to an attribute or an element
         if (!isList(v)) {
@@ -205,7 +205,7 @@ inline const value valueToElement(const value& t) {
         }
 
         // Convert a list value
-        if (isNil((list<value>)v) || !isSymbol(car<value>(v)))
+        if (isNull((list<value>)v) || !isSymbol(car<value>(v)))
             return cons(element, cons(n, mklist<value>(valuesToElements(v))));
 
         // Convert a nested name value pair value
@@ -222,7 +222,7 @@ inline const value valueToElement(const value& t) {
  * Convert a list of values to a list of elements.
  */
 inline const list<value> valuesToElements(const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons<value>(valueToElement(car(l)), valuesToElements(cdr(l)));
 }
@@ -234,7 +234,7 @@ inline const value attributeValue(const value& name, const list<value>& l) {
     const list<value> f = filter<value>([name](const value& v) {
                 return isAttribute(v) && attributeName((list<value>)v) == name;
            }, l);
-    if (isNil(f))
+    if (isNull(f))
         return nilValue;
     return caddr<value>(car(f));
 }
@@ -253,7 +253,7 @@ inline const list<value> elementChildren(const value& name, const list<value>& l
  */
 inline const value elementChild(const value& name, const list<value>& l) {
     const list<value> f = elementChildren(name, l);
-    if (isNil(f))
+    if (isNull(f))
         return nilValue;
     return car(f);
 }
diff --git a/sca-cpp/trunk/kernel/function.hpp b/sca-cpp/trunk/kernel/function.hpp
index 0a88cf51d9..e2ba8ad0ad 100644
--- a/sca-cpp/trunk/kernel/function.hpp
+++ b/sca-cpp/trunk/kernel/function.hpp
@@ -160,7 +160,7 @@ public:
     }
 
     template<typename S> friend ostream& operator<<(ostream&, const lambda<S>&);
-    template<typename S> friend const bool isNil(const lambda<S>& l) noexcept;
+    template<typename S> friend const bool isNull(const lambda<S>& l) noexcept;
 
 private:
     typedef Callable<R,P...> CallableType;
@@ -179,7 +179,7 @@ template<typename S> inline ostream& operator<<(ostream& out, const lambda<S>& l
 /**
  * Return true if a lambda is nil.
  */
-template<typename S> inline const bool isNil(const lambda<S>& l) noexcept {
+template<typename S> inline const bool isNull(const lambda<S>& l) noexcept {
     return (const void*)l.callable == NULL;
 }
 
diff --git a/sca-cpp/trunk/kernel/kernel-test.cpp b/sca-cpp/trunk/kernel/kernel-test.cpp
index 4c68975961..5d8b8039b4 100644
--- a/sca-cpp/trunk/kernel/kernel-test.cpp
+++ b/sca-cpp/trunk/kernel/kernel-test.cpp
@@ -225,7 +225,7 @@ const bool testMutable() {
     }
     {
         gc_mutable_ref<value> v;
-        assert(isNil((value)v));
+        assert(isNull((value)v));
         v = 1;
         assert(v == 1);
     }
@@ -386,7 +386,7 @@ ostream& operator<<(ostream& out, const Element& v) {
 const bool testCons() {
     assert(car(cons(2, mklist(3))) == 2);
     assert(car(cdr(cons(2, mklist(3)))) == 3);
-    assert(isNil(cdr(cdr(cons(2, mklist(3))))));
+    assert(isNull(cdr(cdr(cons(2, mklist(3))))));
 
     assert(cons(Element(1), mklist(Element(2))) == mklist(Element(1), Element(2)));
     return true;
@@ -471,7 +471,7 @@ const bool testAppend() {
     assert(car(append(mklist(1), mklist(2))) == 1);
     assert(car(cdr(append(mklist(1), mklist(2)))) == 2);
     assert(car(cdr(cdr(append(mklist(1), mklist(2, 3))))) == 3);
-    assert(isNil(cdr(cdr(cdr(append(mklist(1), mklist(2, 3)))))));
+    assert(isNull(cdr(cdr(cdr(append(mklist(1), mklist(2, 3)))))));
 
     assert(list<int>() + 1 + 2 + 3 == mklist(1, 2, 3));
     return true;
@@ -497,12 +497,12 @@ const bool testComplex() {
     const list<Complex> p = mklist(Complex(1, 2), Complex(3, 4));
     assert(car(p).x == 1);
     assert(car(cdr(p)).x == 3);
-    assert(isNil(cdr(cdr(p))));
+    assert(isNull(cdr(cdr(p))));
     return true;
 }
 
 const bool testMap() {
-    assert(isNil(map<int, int>(square, list<int>())));
+    assert(isNull(map<int, int>(square, list<int>())));
 
     const list<int> m = map<int, int>(square, mklist(2, 3));
     assert(car(m) == 4);
@@ -535,7 +535,7 @@ const bool testFilter() {
 }
 
 const bool testMember() {
-    assert(isNil(member(4, mklist(1, 2, 3))));
+    assert(isNull(member(4, mklist(1, 2, 3))));
     assert(car(member(1, mklist(1, 2, 3))) == 1);
     assert(car(member(2, mklist(1, 2, 3))) == 2);
     assert(car(member(3, mklist(1, 2, 3))) == 3);
@@ -543,7 +543,7 @@ const bool testMember() {
 }
 
 const bool testReverse() {
-    assert(isNil(reverse(list<int>())));
+    assert(isNull(reverse(list<int>())));
     assert(car(reverse(mklist(1, 2, 3))) == 3);
     assert(cadr(reverse(mklist(1, 2, 3))) == 2);
     return true;
@@ -566,7 +566,7 @@ const bool testSubst() {
 const bool testAssoc() {
     const list<list<string> > l = mklist(mklist<string>("x", "X"), mklist<string>("a", "A"), mklist<string>("y", "Y"), mklist<string>("a", "AA"));
     assert(assoc<string>("a", l) == mklist<string>("a", "A"));
-    assert(isNil(assoc<string>("z", l)));
+    assert(isNull(assoc<string>("z", l)));
 
     const list<list<string> > l3 = mklist(mklist<string>("x", "X"), mklist<string>("a", "A"), mklist<string>("a", "AA"));
     assert(delAssoc<string>("y", l) == l3);
@@ -762,7 +762,7 @@ const bool testBinaryTreeAssoc() {
     assert(rbtreeAssoc<value>("a", bt) == mklist<value>("a", "aa"));
     assert(rbtreeAssoc<value>("b", bt) == mklist<value>("b", "bb"));
     assert(rbtreeAssoc<value>("f", bt) == mklist<value>("f", "ff"));
-    assert(isNil(rbtreeAssoc<value>("x", bt)));
+    assert(isNull(rbtreeAssoc<value>("x", bt)));
     return true;
 }
 
diff --git a/sca-cpp/trunk/kernel/list.hpp b/sca-cpp/trunk/kernel/list.hpp
index 02df2c2dc5..753b33b6a0 100644
--- a/sca-cpp/trunk/kernel/list.hpp
+++ b/sca-cpp/trunk/kernel/list.hpp
@@ -120,9 +120,9 @@ public:
     inline const bool operator==(const list<T>& p) const noexcept {
         if(this == &p)
             return true;
-        if(isNil(cdr))
-            return isNil(p.cdr);
-        if(isNil(p.cdr))
+        if(isNull(cdr))
+            return isNull(p.cdr);
+        if(isNull(p.cdr))
             return false;
         if(!(car == p.car))
             return false;
@@ -134,9 +134,9 @@ public:
     inline const bool operator<(const list<T>& p) const noexcept {
         if(this == &p)
             return false;
-        if (isNil(cdr))
-            return !isNil(p.cdr);
-        if (isNil(p.cdr))
+        if (isNull(cdr))
+            return !isNull(p.cdr);
+        if (isNull(p.cdr))
             return false;
         if (car < p.car)
             return true;
@@ -148,9 +148,9 @@ public:
     inline const bool operator>(const list<T>& p) const noexcept {
         if(this == &p)
             return false;
-        if (isNil(cdr))
+        if (isNull(cdr))
             return false;
-        if (isNil(p.cdr))
+        if (isNull(p.cdr))
             return true;
         if (car > p.car)
             return true;
@@ -173,7 +173,7 @@ private:
     string watch;
 #endif
 
-    template<typename X> friend const bool isNil(const list<X>& p) noexcept;
+    template<typename X> friend const bool isNull(const list<X>& p) noexcept;
     template<typename X> friend const X car(const list<X>& p) noexcept;
     template<typename X> friend const list<X> cdr(const list<X>& p) noexcept;
 
@@ -188,7 +188,7 @@ private:
  * to watch than the list itself in a debugger.
  */
 template<typename T> inline const string watchList(const list<T>& p) noexcept {
-    if(isNil(p))
+    if(isNull(p))
         return "()";
     odebugstream os;
     os << "(" << car(p) << " ...)";
@@ -200,22 +200,22 @@ template<typename T> inline const string watchList(const list<T>& p) noexcept {
 /**
  * Returns true if the given list is nil.
  */
-template<typename T> inline const bool isNil(const list<T>& p) noexcept {
-    return isNil(p.cdr);
+template<typename T> inline const bool isNull(const list<T>& p) noexcept {
+    return isNull(p.cdr);
 }
 
 /**
  * Write a list to an output stream.
  */
 template<typename T> inline ostream& writeHelper(ostream& out, const list<T>& l) noexcept {
-    if (isNil(l))
+    if (isNull(l))
         return out;
     out << " " << car(l);
     return writeHelper(out, cdr(l));
 }
 
 template<typename T> inline ostream& operator<<(ostream& out, const list<T>& l) noexcept {
-    if(isNil(l))
+    if(isNull(l))
         return out << "()";
     out << "(" << car(l);
     writeHelper<T>(out, cdr(l));
@@ -294,7 +294,7 @@ template<typename T> inline const list<T> mklist(const T& a, const T& b, const T
  */
 template<typename T> inline const T car(const list<T>& p) noexcept {
     // Abort if trying to access the car of a nil list
-    assertOrFail(!isNil(p.cdr));
+    assertOrFail(!isNull(p.cdr));
     return p.car;
 }
 
@@ -401,7 +401,7 @@ template<typename T> inline const list<T> cdddddddr(const list<T>& p) noexcept {
  */
 template<typename T> inline const size_t length(const list<T>& p) noexcept {
     const lambda<size_t(const size_t, const list<T>&)> lengthRef = [&lengthRef](const size_t c, const list<T>& p) -> const size_t {
-        if(isNil(p))
+        if(isNull(p))
             return c;
         return lengthRef(c + 1, cdr(p));
     };
@@ -412,7 +412,7 @@ template<typename T> inline const size_t length(const list<T>& p) noexcept {
  * Appends a list and a lambda function returning a list.
  */
 template<typename T> inline const list<T> append(const list<T>&a, const lambda<const list<T>()>& fb) noexcept {
-    if(isNil(a))
+    if(isNull(a))
         return fb();
     return cons<T>(car(a), [a, fb]() { return append(cdr(a), fb); });
 }
@@ -439,7 +439,7 @@ template<typename T, typename V> const list<T> inline operator+(const list<T>& l
  * Run a map lambda function on a list.
  */
 template<typename T, typename R> inline const list<R> map(const lambda<const R(const T)>& f, const list<T>& p) noexcept {
-    if(isNil(p))
+    if(isNull(p))
         return list<R> ();
     return cons(f(car(p)), map(f, cdr(p)));
 }
@@ -449,7 +449,7 @@ template<typename T, typename R> inline const list<R> map(const lambda<const R(c
  */
 template<typename T, typename R> inline const R reduce(const lambda<const R(const R, const T)>& f, const R& initial, const list<T>& p) noexcept {
     const lambda<const R(const R&, const list<T>&p)> reduceAccumulate = [f, &reduceAccumulate](const R& acc, const list<T>& p) -> R {
-        if(isNil(p))
+        if(isNull(p))
             return acc;
         return reduceAccumulate(f(acc, car(p)), cdr(p));
     };
@@ -458,7 +458,7 @@ template<typename T, typename R> inline const R reduce(const lambda<const R(cons
 
 template<typename T, typename R> inline const R reduceRight(const lambda<const R(const T, const R)>& f, const R& initial, const list<T>& p) noexcept {
     const lambda<const R(const list<T>&p, const R&)> reduceRightAccumulate = [f, &reduceRightAccumulate](const list<T>& p, const R& acc) -> R {
-        if(isNil(p))
+        if(isNull(p))
             return acc;
         return reduceRightAccumulate(cdr(p), f(car(p), acc));
     };
@@ -469,7 +469,7 @@ template<typename T, typename R> inline const R reduceRight(const lambda<const R
  * Run a filter lambda function on a list.
  */
 template<typename T> inline const list<T> filter(const lambda<const bool(const T)>& f, const list<T>& p) noexcept {
-    if(isNil(p))
+    if(isNull(p))
         return list<T> ();
     if(f(car(p))) {
         const lambda<const list<T>(const lambda<const bool(const T)>, const list<T>)> ff(filter<T>);
@@ -482,7 +482,7 @@ template<typename T> inline const list<T> filter(const lambda<const bool(const T
  * Returns a list pointing to a member of a list.
  */
 template<typename T> inline const list<T> member(const T& t, const list<T>& p) noexcept {
-    if(isNil(p))
+    if(isNull(p))
         return list<T> ();
     if(t == car(p))
         return p;
@@ -493,7 +493,7 @@ template<typename T> inline const list<T> member(const T& t, const list<T>& p) n
  * Reverse a list.
  */
 template<typename T> inline const list<T> reverseIter(const list<T>& acc, const list<T>& p) noexcept {
-    if(isNil(p))
+    if(isNull(p))
         return acc;
     return reverseIter(cons(car(p), acc), cdr(p));
 }
@@ -528,7 +528,7 @@ template<typename T> inline const T listRef(const list<T>& l, const size_t i) no
 template<typename T> inline const list<T> listTail(const list<T>& l, const size_t k) noexcept {
     if(k == 0)
         return l;
-    if(isNil(l))
+    if(isNull(l))
         return l;
     return listTail(cdr(l), k - 1);
 }
@@ -537,7 +537,7 @@ template<typename T> inline const list<T> listTail(const list<T>& l, const size_
  * Substitute elements in a list.
  */
 template<typename T> inline const list<T> subst(const T& o, const T& n, const list<T>& p) noexcept {
-    if(isNil(p))
+    if(isNull(p))
         return p;
     if(o == car(p))
         return cons<T>(n, subst(o, n, cdr(p)));
@@ -548,7 +548,7 @@ template<typename T> inline const list<T> subst(const T& o, const T& n, const li
  * Returns the first pair matching a key from a list of key value pairs.
  */
 template<typename T> inline const list<T> assoc(const T& k, const list<list<T> >& p) noexcept {
-    if(isNil(p))
+    if(isNull(p))
         return list<T>();
     if(k == car(car(p)))
         return car(p);
@@ -560,7 +560,7 @@ template<typename T> inline const list<T> assoc(const T& k, const list<list<T> >
  * Requires T to support isList and cast to list<T>.
  */
 template<typename T> inline const list<T> assoc(const T& k, const list<T>& p) noexcept {
-    if(isNil(p))
+    if(isNull(p))
         return list<T>();
     const T c = car(p);
     if(isList(c) && k == car<T>(c))
@@ -572,7 +572,7 @@ template<typename T> inline const list<T> assoc(const T& k, const list<T>& p) no
  * Returns a list of lists containing elements from two input lists.
  */
 template<typename T> inline const list<list<T> > zip(const list<T>& a, const list<T>& b) noexcept {
-    if (isNil(a) || isNil(b))
+    if (isNull(a) || isNull(b))
         return list<list<T> >();
     return cons<list<T> >(mklist<T>(car(a), car(b)), zip(cdr(a), cdr(b)));
 }
@@ -581,13 +581,13 @@ template<typename T> inline const list<list<T> > zip(const list<T>& a, const lis
  * Converts a list of key value pairs to a list containing the list of keys and the list of values.
  */
 template<typename T> inline const list<T> unzipKeys(const list<list<T> >& l) noexcept {
-    if (isNil(l))
+    if (isNull(l))
         return list<T>();
     return cons(car(car(l)), unzipKeys(cdr(l)));
 }
 
 template<typename T> inline const list<T> unzipValues(const list<list<T> >& l) noexcept {
-    if (isNil(l))
+    if (isNull(l))
         return list<T>();
     return cons(cadr(car(l)), unzipValues(cdr(l)));
 }
@@ -600,7 +600,7 @@ template<typename T> inline const list<list<T> > unzip(const list<list<T> >& l)
  * Delete assocs matching a key from a list of assocs.
  */
 template<typename T> inline const list<list<T> > delAssoc(const T& k, const list<list<T> >& p) noexcept {
-    if(isNil(p))
+    if(isNull(p))
         return p;
     if(k == car(car(p)))
         return delAssoc(k, cdr(p));
@@ -612,7 +612,7 @@ template<typename T> inline const list<list<T> > delAssoc(const T& k, const list
  * Requires T to support isList, isAssoc, and cast to list<T>.
  */
 template<typename T> inline const list<T> delAssoc(const T& k, const list<T>& p) noexcept {
-    if(isNil(p))
+    if(isNull(p))
         return p;
     const T c = car(p);
     if(isList(c) && k == car<T>(c))
@@ -624,7 +624,7 @@ template<typename T> inline const list<T> delAssoc(const T& k, const list<T>& p)
  * Substitute assocs with matching keys in a list of assocs.
  */
 template<typename T> inline const list<list<T> > substAssoc(const T& k, const list<T>& n, const list<list<T> >& p, const bool add = false) noexcept {
-    if(isNil(p))
+    if(isNull(p))
         return add? mklist<list<T> >(n) : p;
     if(k == car(car(p)))
         return cons<list<T> >(n, substAssoc(k, n, cdr(p), false));
@@ -636,7 +636,7 @@ template<typename T> inline const list<list<T> > substAssoc(const T& k, const li
  * Requires T to support isList, isAssoc, and cast to list<T>.
  */
 template<typename T> inline const list<T> substAssoc(const T& k, const list<T>& n, const list<T>& p, const bool add = false) noexcept {
-    if(isNil(p))
+    if(isNull(p))
         return add? mklist<T>(n) : p;
     const T c = car(p);
     if(isList(c) && k == car<T>(c))
diff --git a/sca-cpp/trunk/kernel/parallel-test.cpp b/sca-cpp/trunk/kernel/parallel-test.cpp
index 895bb91eb8..9440cbaafd 100644
--- a/sca-cpp/trunk/kernel/parallel-test.cpp
+++ b/sca-cpp/trunk/kernel/parallel-test.cpp
@@ -109,7 +109,7 @@ const list<future<int> > submitSquares(worker& w, const int max, const int i) {
 }
 
 bool checkSquareResults(const list<future<int> > r, int i) {
-    if (isNil(r))
+    if (isNull(r))
         return true;
     assert(car(r) == i * i);
     checkSquareResults(cdr(r), i + 1);
@@ -160,7 +160,7 @@ const list<future<long int> > submitTLSSets(worker& w, wqueue<bool>& wq, wqueue<
 }
 
 const bool checkTLSSets(const list<future<long int> > s) {
-    if (isNil(s))
+    if (isNull(s))
         return true;
     assert(car(s) == 0);
     return checkTLSSets(cdr(s));
@@ -174,7 +174,7 @@ const list<future<bool> > submitTLSChecks(worker& w, wqueue<bool>& wq, wqueue<bo
 }
 
 const bool checkTLSResults(const list<future<bool> > r) {
-    if (isNil(r))
+    if (isNull(r))
         return true;
     assert(car(r) == true);
     return checkTLSResults(cdr(r));
diff --git a/sca-cpp/trunk/kernel/parallel.hpp b/sca-cpp/trunk/kernel/parallel.hpp
index 8b01bb819f..6981a67831 100644
--- a/sca-cpp/trunk/kernel/parallel.hpp
+++ b/sca-cpp/trunk/kernel/parallel.hpp
@@ -274,7 +274,7 @@ template<typename R> inline const future<R> submit(const worker& w, const lambda
  * Enqueues shutdown requests.
  */
 inline const bool shutdownEnqueue(const list<pthread_t>& threads, wqueue<blambda>& work) noexcept {
-    if (isNil(threads))
+    if (isNull(threads))
         return true;
     enqueue(work, result(false));
     return shutdownEnqueue(cdr(threads), work);
@@ -284,7 +284,7 @@ inline const bool shutdownEnqueue(const list<pthread_t>& threads, wqueue<blambda
  * Waits for shut down threads to terminate.
  */
 inline const bool shutdownJoin(const list<pthread_t>& threads) noexcept {
-    if (isNil(threads))
+    if (isNull(threads))
         return true;
     pthread_join(car(threads), NULL);
     return shutdownJoin(cdr(threads));
@@ -303,7 +303,7 @@ inline const bool shutdown(const worker& w) noexcept {
  * Cancel a worker.
  */
 inline const bool cancel(const list<pthread_t>& threads) noexcept {
-    if (isNil(threads))
+    if (isNull(threads))
         return true;
     pthread_cancel(car(threads));
     return cancel(cdr(threads));
diff --git a/sca-cpp/trunk/kernel/sstream.hpp b/sca-cpp/trunk/kernel/sstream.hpp
index dbdc7414a1..56f1c1c867 100644
--- a/sca-cpp/trunk/kernel/sstream.hpp
+++ b/sca-cpp/trunk/kernel/sstream.hpp
@@ -46,7 +46,7 @@ inline void* stream_memcpy(void* t, const void* s, const size_t n) {
  * Write a list of strings into a buffer.
  */
 const bool writeList(const list<string>& l, char* const buf) {
-    if (isNil(l))
+    if (isNull(l))
         return true;
     const string c = car(l);
     char* b = buf - length(c);
@@ -114,7 +114,7 @@ public:
 private:
     inline const string str() {
         spill();
-        if (isNil((const list<string>)buf))
+        if (isNull((const list<string>)buf))
             return emptyString;
         char* const sbuf = gc_cnew(len + 1);
         writeList(buf, sbuf + len);
@@ -239,10 +239,10 @@ inline const list<string> tokenize(const char* const sep, const string& str) {
 inline const string join(const char* const sep, const list<string>& l) {
     ostringstream os;
     const lambda<ostringstream&(const char* const, const list<string>&, ostringstream&)> join = [&join](const char* const sep, const list<string>& l, ostringstream& os) -> ostringstream& {
-        if (isNil(l))
+        if (isNull(l))
             return os;
         os << car(l);
-        if (!isNil(cdr(l)))
+        if (!isNull(cdr(l)))
             os << sep;
         return join(sep, cdr(l), os);
     };
@@ -277,7 +277,7 @@ inline const list<string> fragment(const list<string>& l, const size_t max) {
  * Write a list of strings to an output stream.
  */
 inline ostream& write(const list<string>& l, ostream& os) {
-    if(isNil(l))
+    if(isNull(l))
         return os;
     os << car(l);
     return write(cdr(l), os);
@@ -287,9 +287,9 @@ inline ostream& write(const list<string>& l, ostream& os) {
  * Convert a list of strings to a string.
  */
 inline const string write(const list<string>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return emptyString;
-    if (isNil(cdr(l)))
+    if (isNull(cdr(l)))
         return car(l);
     ostringstream os;
     write(l, os);
diff --git a/sca-cpp/trunk/kernel/tree.hpp b/sca-cpp/trunk/kernel/tree.hpp
index d350879ce7..a5d0e3d5b0 100644
--- a/sca-cpp/trunk/kernel/tree.hpp
+++ b/sca-cpp/trunk/kernel/tree.hpp
@@ -40,13 +40,13 @@ namespace tuscany {
  * Requires T to support isList, isAssoc, and cast to list<T>.
  */
 template<typename T> inline const list<T> treeDelAssoc(const list<T>& k, const list<T>& l) noexcept {
-    if (isNil(k) || isNil(l))
+    if (isNull(k) || isNull(l))
         return l;
     const list<T> lv = l;
 
     // If list is an assoc and matches, skip it
     if (isAssoc(lv)) {
-        if (car<T>(lv) == car(k) && isNil(cdr(k)))
+        if (car<T>(lv) == car(k) && isNull(cdr(k)))
             return list<T>();
     }
 
@@ -56,23 +56,23 @@ template<typename T> inline const list<T> treeDelAssoc(const list<T>& k, const l
         if (!isList(a))
             return cons<T>(a, treeDelAssoc<T>(k, cdr(lv)));
         const list<T> da = treeDelAssoc<T>(k, a);
-        return isNil(da)? treeDelAssoc<T>(k, cdr(lv)) : cons<T>(da, treeDelAssoc<T>(k, cdr(lv)));
+        return isNull(da)? treeDelAssoc<T>(k, cdr(lv)) : cons<T>(da, treeDelAssoc<T>(k, cdr(lv)));
     }
 
     // If we found a match, skip it and lookup children and rest of the list
     if (car<T>(a) == car(k)) {
-        if (isNil(cdr(k)))
+        if (isNull(cdr(k)))
             return treeDelAssoc<T>(k, cdr(lv));
         return cons<T>(cons<T>(car<T>(a), treeDelAssoc<T>(cdr(k), cdr<T>(a))), treeDelAssoc<T>(k, cdr(lv)));
     }
 
     // No match, lookup children and rest of the list
-    if (isNil(cdr<T>(a)))
+    if (isNull(cdr<T>(a)))
         return cons<T>(a, treeDelAssoc<T>(k, cdr(lv)));
     if (!isList(cadr<T>(a)))
         return cons<T>(cons<T>(car<T>(a), cons<T>(cadr<T>(a), treeDelAssoc<T>(k, cddr<T>(a)))), treeDelAssoc<T>(k, cdr(lv)));
     const list<T> da = treeDelAssoc<T>(k, cadr<T>(a));
-    if (isNil(da))
+    if (isNull(da))
         return cons<T>(cons<T>(car<T>(a), treeDelAssoc<T>(k, cddr<T>(a))), treeDelAssoc<T>(k, cdr(lv)));
     return cons<T>(cons<T>(car<T>(a), cons<T>(da, treeDelAssoc<T>(k, cddr<T>(a)))), treeDelAssoc<T>(k, cdr(lv)));
 }
@@ -83,12 +83,12 @@ template<typename T> inline const list<T> treeDelAssoc(const list<T>& k, const l
  * Requires T to support isList, isAssoc, and cast to list<T>.
  */
 template<typename T> inline const list<T> treeSubstAssoc(const list<T>& k, const list<T>& n, const list<T>& lv) noexcept {
-    if (isNil(k) || isNil(lv))
+    if (isNull(k) || isNull(lv))
         return lv;
 
     // If list is an assoc and matches, substitute it
     if (isAssoc(lv)) {
-        if (car<T>(lv) == car(k) && isNil(cdr(k)))
+        if (car<T>(lv) == car(k) && isNull(cdr(k)))
             return n;
     }
 
@@ -102,13 +102,13 @@ template<typename T> inline const list<T> treeSubstAssoc(const list<T>& k, const
 
     // If we found a match, substitute it and lookup children and rest of the list
     if (car<T>(a) == car(k)) {
-        if (isNil(cdr(k)))
+        if (isNull(cdr(k)))
             return cons<T>(n, treeSubstAssoc<T>(k, n, cdr(lv)));
         return cons<T>(cons<T>(car<T>(a), treeSubstAssoc<T>(cdr(k), n, cdr<T>(a))), treeSubstAssoc<T>(k, n, cdr(lv)));
     }
 
     // No match, lookup children and rest of the list
-    if (isNil(cdr<T>(a)))
+    if (isNull(cdr<T>(a)))
         return cons<T>(a, treeSubstAssoc<T>(k, n, cdr(lv)));
     if (!isList(cadr<T>(a)))
         return cons<T>(cons<T>(car<T>(a), cons<T>(cadr<T>(a), treeSubstAssoc<T>(k, n, cddr<T>(a)))), treeSubstAssoc<T>(k, n, cdr(lv)));
@@ -121,12 +121,12 @@ template<typename T> inline const list<T> treeSubstAssoc(const list<T>& k, const
  * Requires T to support isList, isAssoc, and cast to list<T>.
  */
 template<typename T> inline const list<T> treeSelectAssoc(const list<T>& k, const list<T>& lv) noexcept {
-    if (isNil(k) || isNil(lv))
+    if (isNull(k) || isNull(lv))
         return list<T>();
 
     // If list is an assoc and matches, select it
     if (isAssoc(lv)) {
-        if (car<T>(lv) == car(k) && isNil(cdr(k)))
+        if (car<T>(lv) == car(k) && isNull(cdr(k)))
             return mklist<T>(lv);
     }
 
@@ -140,13 +140,13 @@ template<typename T> inline const list<T> treeSelectAssoc(const list<T>& k, cons
 
     // If we found a match, select it and lookup children and rest of the list
     if (car<T>(a) == car(k)) {
-        if (isNil(cdr(k)))
+        if (isNull(cdr(k)))
             return cons<T>(a, treeSelectAssoc<T>(k, cdr(lv)));
         return append<T>(treeSelectAssoc<T>(cdr(k), cdr<T>(a)), treeSelectAssoc<T>(k, cdr(lv)));
     }
 
     // No match, lookup children and rest of the list
-    if (isNil(cdr<T>(a)))
+    if (isNull(cdr<T>(a)))
         return treeSelectAssoc<T>(k, cdr(lv));
     if (!isList(cadr<T>(a)))
         return append<T>(treeSelectAssoc<T>(k, cddr<T>(a)), treeSelectAssoc<T>(k, cdr(lv)));
@@ -164,7 +164,7 @@ template<typename T> inline const list<T> mkrbtree(const T& e, const list<T>& le
  * Find a leaf with the given key in a rooted binary tree.
  */
 template<typename T> inline const list<T> rbtreeAssoc(const T& k, const list<T>& tree) {
-    if (isNil(tree))
+    if (isNull(tree))
         return tree;
     if (k == car<T>(car(tree)))
         return car(tree);
@@ -177,7 +177,7 @@ template<typename T> inline const list<T> rbtreeAssoc(const T& k, const list<T>&
  * Construct a new rooted binary tree from a leaf and a tree.
  */
 template<typename T> inline const list<T> rbtreeCons(const T& e, const list<T>& tree) {
-    if (isNil(tree))
+    if (isNull(tree))
         return mkrbtree(e, list<T>(), list<T>());
     if (e == car(tree))
         return tree;
@@ -190,7 +190,7 @@ template<typename T> inline const list<T> rbtreeCons(const T& e, const list<T>&
  * Make a rooted binary tree from an unordered list of leaves.
  */
 template<typename T> inline const list<T> mkrbtree(const list<T>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return rbtreeCons(car(l), mkrbtree(cdr(l)));
 }
@@ -199,7 +199,7 @@ template<typename T> inline const list<T> mkrbtree(const list<T>& l) {
  * Convert a rooted binary tree to an ordered list of leaves.
  */
 template<typename T> inline const list<T> flatten(const list<T>& tree) {
-    if (isNil(tree))
+    if (isNull(tree))
         return tree;
     return append<T>(flatten<T>(cadr(tree)), cons<T>(car(tree), flatten<T>(caddr(tree))));
 }
diff --git a/sca-cpp/trunk/kernel/value.hpp b/sca-cpp/trunk/kernel/value.hpp
index d5ce34084a..660ece0c25 100644
--- a/sca-cpp/trunk/kernel/value.hpp
+++ b/sca-cpp/trunk/kernel/value.hpp
@@ -489,7 +489,7 @@ inline const value::ValueType type(const value& v) noexcept {
 /**
  * Returns true if a value is nil.
  */
-inline const bool isNil(const value& v) noexcept {
+inline const bool isNull(const value& v) noexcept {
     return type(v) == value::Nil;
 }
 
@@ -546,7 +546,7 @@ inline const bool isPtr(const value& v) noexcept {
  * Returns true if a value is a tagged list.
  */
 inline const bool isTaggedList(const value& exp, const value& tag) noexcept {
-    if(isList(exp) && !isNil((list<value>)exp))
+    if(isList(exp) && !isNull((list<value>)exp))
         return car((list<value>)exp) == tag;
     return false;
 }
@@ -555,14 +555,14 @@ inline const bool isTaggedList(const value& exp, const value& tag) noexcept {
  * Returns true if a value is an assoc.
  */
 inline const bool isAssoc(const value& exp) noexcept {
-    return isList(exp) && !isNil((list<value>)exp) && isSymbol(car<value>(exp));
+    return isList(exp) && !isNull((list<value>)exp) && isSymbol(car<value>(exp));
 }
 
 /**
  * Make a list of values from a list of other things.
  */
 template<typename T> inline const list<value> mkvalues(const list<T>& l) noexcept {
-    if (isNil(l))
+    if (isNull(l))
         return nilListValue;
     return cons<value>(car(l), mkvalues(cdr(l)));
 }
@@ -571,7 +571,7 @@ template<typename T> inline const list<value> mkvalues(const list<T>& l) noexcep
  * Convert a list of values to a list of other things.
  */
 template<typename T> inline const list<T> convertValues(const list<value>& l) noexcept {
-    if (isNil(l))
+    if (isNull(l))
         return list<T>();
     return cons<T>(car(l), convertValues<T>(cdr(l)));
 }
@@ -580,7 +580,7 @@ template<typename T> inline const list<T> convertValues(const list<value>& l) no
  * Convert a list of lists of values to a list of values.
  */
 inline const list<value> listOfValues(const list<list<value> >& l) noexcept {
-    if (isNil(l))
+    if (isNull(l))
         return nilListValue;
     return cons<value>(car(l), listOfValues(cdr(l)));
 }
@@ -589,7 +589,7 @@ inline const list<value> listOfValues(const list<list<value> >& l) noexcept {
  * Convert a list of values to a list of lists of values.
  */
 inline const list<list<value> > listOfListOfValues(const list<value>& l) noexcept {
-    if (isNil(l))
+    if (isNull(l))
         return list<list<value> >();
     return cons<list<value> >(type(car(l)) == value::List? list<value>(car(l)) : nilPairValue, listOfListOfValues(cdr(l)));
 }
@@ -613,7 +613,7 @@ inline const list<value> pathValues(const value& p) noexcept {
  * Convert a path represented as a list of values to a string value.
  */
 inline const value path(const list<value>& p) noexcept {
-    if (isNil(p))
+    if (isNull(p))
         return emptyString;
     return string("/") + (string)car(p) + (string)path(cdr(p));
 }
diff --git a/sca-cpp/trunk/modules/atom/atom.hpp b/sca-cpp/trunk/modules/atom/atom.hpp
index 259769e2cb..b6f2788b1e 100644
--- a/sca-cpp/trunk/modules/atom/atom.hpp
+++ b/sca-cpp/trunk/modules/atom/atom.hpp
@@ -46,22 +46,22 @@ const value entry("entry");
  */
 const list<value> entryElementValues(const list<value>& e) {
     const list<value> lt = elementChildren("title", e);
-    const list<value> t = nilListValue + element + value("title") + (isNil(lt)? value(emptyString) : elementValue(car(lt)));
+    const list<value> t = nilListValue + element + value("title") + (isNull(lt)? value(emptyString) : elementValue(car(lt)));
 
     const list<value> li = elementChildren("id", e);
-    const list<value> i = nilListValue + element + value("id") + (isNil(li)? value(emptyString) : elementValue(car(li)));
+    const list<value> i = nilListValue + element + value("id") + (isNull(li)? value(emptyString) : elementValue(car(li)));
 
     const list<value> la = elementChildren("author", e);
-    const list<value> lan = isNil(la)? nilListValue : elementChildren("name", car(la));
-    const list<value> lae = isNil(la)? nilListValue : elementChildren("email", car(la));
-    const list<value> laa = isNil(lan)? lae : lan;
-    const list<value> a = isNil(laa)? nilListValue : mklist<value>(nilListValue + element + value("author") + elementValue(car(laa)));
+    const list<value> lan = isNull(la)? nilListValue : elementChildren("name", car(la));
+    const list<value> lae = isNull(la)? nilListValue : elementChildren("email", car(la));
+    const list<value> laa = isNull(lan)? lae : lan;
+    const list<value> a = isNull(laa)? nilListValue : mklist<value>(nilListValue + element + value("author") + elementValue(car(laa)));
 
     const list<value> lu = elementChildren("updated", e);
-    const list<value> u = isNil(lu)? nilListValue : mklist<value>(nilListValue + element + value("updated") + elementValue(car(lu)));
+    const list<value> u = isNull(lu)? nilListValue : mklist<value>(nilListValue + element + value("updated") + elementValue(car(lu)));
 
     const list<value> lc = elementChildren("content", e);
-    const list<value> c = isNil(lc)? nilListValue : isAttribute(elementValue(car(lc)))? nilListValue :
+    const list<value> c = isNull(lc)? nilListValue : isAttribute(elementValue(car(lc)))? nilListValue :
         mklist<value>(nilListValue + element + value("content") + elementValue(car(lc)));
 
     return append<value>(append<value>(append<value>(nilListValue + element + entry + value(t) + value(i), a), u), c);
@@ -71,7 +71,7 @@ const list<value> entryElementValues(const list<value>& e) {
  * Convert a list of elements to a list of element values representing ATOM entries.
  */
 const list<value> entriesElementValues(const list<value>& e) {
-    if (isNil(e))
+    if (isNull(e))
         return e;
     return cons<value>(entryElementValues(car(e)), entriesElementValues(cdr(e)));
 }
@@ -99,7 +99,7 @@ const bool isATOMEntry(const list<string>& ls) {
  */
 const failable<list<value> > readATOMEntry(const list<string>& ilist) {
     const list<value> e = content(xml::readElements(ilist));
-    if (isNil(e))
+    if (isNull(e))
         return mkfailure<list<value> >("Empty entry");
     return mklist<value>(entryElementValues(car(e)));
 }
@@ -109,7 +109,7 @@ const failable<list<value> > readATOMEntry(const list<string>& ilist) {
  */
 const failable<list<value> > readATOMFeed(const list<string>& ilist) {
     const list<value> f = content(xml::readElements(ilist));
-    if (isNil(f))
+    if (isNull(f))
         return mkfailure<list<value> >("Empty feed");
     const list<value> t = elementChildren("title", car(f));
     const list<value> i = elementChildren("id", car(f));
@@ -136,18 +136,18 @@ const list<value> entryElement(const list<value>& l) {
     const value title = elementChild("title", l);
     const value id = elementChild("id", l);
     const value author = elementChild("author", l);
-    const bool email = isNil(author)? false : contains(elementValue(author), "@");
+    const bool email = isNull(author)? false : contains(elementValue(author), "@");
     const value updated = elementChild("updated", l);
     const value content = elementChild("content", l);
-    const bool text = isNil(content)? false : elementHasValue(content);
+    const bool text = isNull(content)? false : elementHasValue(content);
     return nilListValue
         + element + entry + (nilListValue + attribute + "xmlns" + "http://www.w3.org/2005/Atom")
         + (nilListValue + element + "title" + (nilListValue + attribute + "type" + "text") + elementValue(title))
         + (nilListValue + element + "id" + elementValue(id))
-        + (isNil(author)? nilListValue : (nilListValue + element + "author" +
+        + (isNull(author)? nilListValue : (nilListValue + element + "author" +
             (email? (nilListValue + element + "email" + elementValue(author)) : (nilListValue + element + "name" + elementValue(author)))))
-        + (isNil(updated)? nilListValue : (nilListValue + element + "updated" + elementValue(updated)))
-        + (isNil(content)?
+        + (isNull(updated)? nilListValue : (nilListValue + element + "updated" + elementValue(updated)))
+        + (isNull(content)?
             nilListValue :
             append<value>(nilListValue + element + "content" + (nilListValue + attribute + "type" + (text? "text" : "application/xml")),
                 text? mklist<value>(elementValue(content)) : contentElementChildren(content)))
@@ -158,7 +158,7 @@ const list<value> entryElement(const list<value>& l) {
  * Convert a list of element values representing ATOM entries to a list of elements.
  */
 const list<value> entriesElements(const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons<value>(entryElement(car(l)), entriesElements(cdr(l)));
 }
@@ -167,7 +167,7 @@ const list<value> entriesElements(const list<value>& l) {
  * Convert a list of element values representing an ATOM entry to an ATOM entry.
  */
 template<typename R> const failable<R> writeATOMEntry(const lambda<const R(const string&, const R)>& reduce, const R& initial, const list<value>& ll) {
-    const list<value> l = isNil(ll)? ll : (list<value>)car(ll);
+    const list<value> l = isNull(ll)? ll : (list<value>)car(ll);
     return xml::writeElements<R>(reduce, initial, mklist<value>(entryElement(l)));
 }
 
@@ -182,11 +182,11 @@ const failable<list<string> > writeATOMEntry(const list<value>& l) {
  * Convert a list of element values representing an ATOM feed to an ATOM feed.
  */
 template<typename R> const failable<R> writeATOMFeed(const lambda<const R(const string&, const R)>& reduce, const R& initial, const list<value>& ll) {
-    const list<value> l = isNil(ll)? ll : (list<value>)car(ll);
+    const list<value> l = isNull(ll)? ll : (list<value>)car(ll);
     const list<value> lt = elementChildren("title", l);
-    const value t = isNil(lt)? value(emptyString) : elementValue(car(lt));
+    const value t = isNull(lt)? value(emptyString) : elementValue(car(lt));
     const list<value> li = elementChildren("id", l);
-    const value i = isNil(li)? value(emptyString) : elementValue(car(li));
+    const value i = isNull(li)? value(emptyString) : elementValue(car(li));
     const list<value> f = nilListValue
         + element + feed + (nilListValue + attribute + "xmlns" + "http://www.w3.org/2005/Atom")
         + (nilListValue + element + "title" + (nilListValue + attribute + "type" + "text") + t)
@@ -194,11 +194,11 @@ template<typename R> const failable<R> writeATOMFeed(const lambda<const R(const
 
     // Write ATOM entries
     const list<value> le = elementChildren(entry, l);
-    if (isNil(le))
+    if (isNull(le))
         return xml::writeElements<R>(reduce, initial, mklist<value>(f));
 
     // Write a single ATOM entry element with a list of values
-    if (!isNil(le) && !isNil(car(le)) && isList(car<value>(caddr<value>(car(le))))) {
+    if (!isNull(le) && !isNull(car(le)) && isList(car<value>(caddr<value>(car(le))))) {
         const list<value> fe = append(f, entriesElements(caddr<value>(car(le))));
         return xml::writeElements<R>(reduce, initial, mklist<value>(fe));
     }
diff --git a/sca-cpp/trunk/modules/http/http.hpp b/sca-cpp/trunk/modules/http/http.hpp
index cd0eb6c04b..04b0d4e490 100644
--- a/sca-cpp/trunk/modules/http/http.hpp
+++ b/sca-cpp/trunk/modules/http/http.hpp
@@ -367,7 +367,7 @@ public:
  */
 size_t readCallback(void *ptr, size_t size, size_t nmemb, void *data) {
     CURLReadContext& rcx = *(CURLReadContext*)data;
-    if (isNil((const list<string>)rcx.ilist))
+    if (isNull((const list<string>)rcx.ilist))
         return 0;
     const list<string> f(fragment(rcx.ilist, size * nmemb));
     const string s = car(f);
@@ -403,7 +403,7 @@ template<typename R> size_t writeCallback(void *ptr, size_t size, size_t nmemb,
  * a reduce function used to process the response.
  */
 curl_slist* headers(curl_slist* const cl, const list<string>& h) {
-    if (isNil(h))
+    if (isNull(h))
         return cl;
     return headers(curl_slist_append(cl, c_str(string(car(h)))), cdr(h));
 }
@@ -508,7 +508,7 @@ const failable<value> evalExpr(const value& expr, const string& url, const CURLS
  * Find and return a header.
  */
 const maybe<string> header(const char* const prefix, const list<string>& h) {
-    if (isNil(h))
+    if (isNull(h))
         return maybe<string>();
     const string s = car(h);
     if (find(s, prefix) != 0)
@@ -676,7 +676,7 @@ const failable<list<list<string> > > contentRequest(const value& c, unused const
 
     // Write in the format requested by the client, if any
     const list<value> fmt = assoc<value>("format", nilListValue);
-    if (!isNil(fmt)) {
+    if (!isNull(fmt)) {
         if (cadr(fmt) == "scheme")
             return writeRequest(scheme::writeValue(c), "text/x-scheme; charset=utf-8");
         if (cadr(fmt) == "json")
@@ -692,26 +692,26 @@ const failable<list<list<string> > > contentRequest(const value& c, unused const
     }
 
     // Write an empty list as a JSON value
-    if (isNil((list<value>)c)) {
+    if (isNull((list<value>)c)) {
         debug(nilListValue, "http::contentRequest::empty");
         return writeRequest(json::writeValue(c), "application/json; charset=utf-8");
     }
 
     // Write content-type / content-list pair
-    if (isString(car<value>(c)) && !isNil(cdr<value>(c)) && isList(cadr<value>(c)))
+    if (isString(car<value>(c)) && !isNull(cdr<value>(c)) && isList(cadr<value>(c)))
         return writeRequest(convertValues<string>(cadr<value>(c)), car<value>(c));
 
     // Write an assoc value as a JSON value
-    if (isSymbol(car<value>(c)) && !isNil(cdr<value>(c))) {
+    if (isSymbol(car<value>(c)) && !isNull(cdr<value>(c))) {
         debug(c, "http::contentRequest::assoc");
         return writeRequest(json::writeValue(c), "application/json; charset=utf-8");
     }
 
     // Write an ATOM feed or entry
     const list<value> e = valuesToElements(c);
-    if (isList(car<value>(e)) && !isNil(car<value>(e))) {
+    if (isList(car<value>(e)) && !isNull(car<value>(e))) {
         const list<value> el = car<value>(e);
-        if (isSymbol(car<value>(el)) && car<value>(el) == element && !isNil(cdr<value>(el)) && isSymbol(cadr<value>(el)) && elementHasChildren(el) && !elementHasValue(el)) {
+        if (isSymbol(car<value>(el)) && car<value>(el) == element && !isNull(cdr<value>(el)) && isSymbol(cadr<value>(el)) && elementHasChildren(el) && !elementHasValue(el)) {
             if (cadr<value>(el) == atom::feed)
                 return writeRequest(atom::writeATOMFeed(e), "application/atom+xml; charset=utf-8");
             if (cadr<value>(el) == atom::entry)
@@ -943,14 +943,14 @@ const failable<size_t> recv(char* const c, const size_t l, const CURLSession& cs
  * Converts a list of key value pairs to a query string.
  */
 ostringstream& queryString(const list<value>& args, ostringstream& os) {
-    if (isNil(args))
+    if (isNull(args))
         return os;
     const list<value> arg = car(args);
     debug(arg, "http::queryString::arg");
-    if (isNil(arg) || isNil(cdr(arg)))
+    if (isNull(arg) || isNull(cdr(arg)))
         return queryString(cdr(args), os);
     os << car(arg) << "=" << c_str(cadr(arg));
-    if (!isNil(cdr(args)))
+    if (!isNull(cdr(args)))
         os << "&";
     return queryString(cdr(args), os);
 }
diff --git a/sca-cpp/trunk/modules/http/httpd.hpp b/sca-cpp/trunk/modules/http/httpd.hpp
index 255f0aa31b..bf06ed5d91 100644
--- a/sca-cpp/trunk/modules/http/httpd.hpp
+++ b/sca-cpp/trunk/modules/http/httpd.hpp
@@ -260,7 +260,7 @@ const string cookie(const request_rec* const r) {
  * Return the remaining part of a uri after the given path (aka the path info.)
  */
 const list<value> pathInfo(const list<value>& uri, const list<value>& path) {
-    if (isNil(path))
+    if (isNull(path))
         return uri;
     return pathInfo(cdr(uri), cdr(path));
 }
@@ -347,14 +347,14 @@ const list<value> unescapeArgs(const list<value>& args) {
 const value queryArg(const string& s) {
     debug(s, "httpd::queryArg::string");
     const list<string> t = tokenize("=", s);
-    if (isNil(cdr(t)))
+    if (isNull(cdr(t)))
         return mklist<value>(c_str(car(t)), emptyString);
     return mklist<value>(c_str(car(t)), cadr(t));
 }
 
 const string fixupQueryArgs(const string& a) {
     const list<string> t = tokenize("?", a);
-    if (isNil(t) || isNil(cdr(t)))
+    if (isNull(t) || isNull(cdr(t)))
         return a;
     return join("&", t);
 }
@@ -376,7 +376,7 @@ const list<value> queryArgs(const request_rec* const r) {
  * Converts the args received in a POST to a list of key value pairs.
  */
 const list<value> postArgs(const list<value>& a) {
-    if (isNil(a))
+    if (isNull(a))
         return nilListValue;
     const list<value> l = car(a);
     return cons<value>(l, postArgs(cdr(a)));
diff --git a/sca-cpp/trunk/modules/http/mod-openauth.cpp b/sca-cpp/trunk/modules/http/mod-openauth.cpp
index 1b70f27744..3adc488301 100644
--- a/sca-cpp/trunk/modules/http/mod-openauth.cpp
+++ b/sca-cpp/trunk/modules/http/mod-openauth.cpp
@@ -127,7 +127,7 @@ static apr_status_t (*ap_session_set_fn)(request_rec * r, session_rec * z, const
  * Run the authnz hooks to authenticate a request.
  */
 const failable<int> checkAuthnzProviders(const string& user, const string& pw, request_rec* const r, const list<AuthnProviderConf>& apcs) {
-    if(isNil(apcs))
+    if(isNull(apcs))
         return mkfailure<int>("Authentication failure for: " + user, HTTP_UNAUTHORIZED);
     const AuthnProviderConf apc = car<AuthnProviderConf>(apcs);
     if(apc.provider == NULL || !apc.provider->check_password)
@@ -145,7 +145,7 @@ const failable<int> checkAuthnz(const string& user, const string& pw, request_re
     if(substr(user, 0, 1) == "/" && pw == "password")
         return mkfailure<int>(string("Encountered FakeBasicAuth spoof: ") + user, HTTP_UNAUTHORIZED);
 
-    if(isNil((const list<AuthnProviderConf>)dc.apcs)) {
+    if(isNull((const list<AuthnProviderConf>)dc.apcs)) {
         const authn_provider* provider = (const authn_provider*)ap_lookup_provider(AUTHN_PROVIDER_GROUP, AUTHN_DEFAULT_PROVIDER, AUTHN_PROVIDER_VERSION);
         return checkAuthnzProviders(user, pw, r, mklist<AuthnProviderConf>(AuthnProviderConf(AUTHN_DEFAULT_PROVIDER, provider)));
     }
@@ -181,10 +181,10 @@ const failable<value> userInfoFromCookie(const value& sid, const string& realm,
     const list<value> info = httpd::queryArgs(sid);
     debug(info, "modopenauth::userInfoFromCookie::info");
     const list<value> user = assoc<value>(realm + "-user", info);
-    if(isNil(user))
+    if(isNull(user))
         return userInfoFromSession(realm, r);
     const list<value> pw = assoc<value>(realm + "-pw", info);
-    if(isNil(pw))
+    if(isNull(pw))
         return mkfailure<value>("Couldn't retrieve password", HTTP_UNAUTHORIZED);
     return value(mklist<value>(mklist<value>("realm", realm), mklist<value>("id", cadr(user)), mklist<value>("password", cadr(pw))));
 }
@@ -217,12 +217,12 @@ const failable<int> authenticated(const list<value>& info, request_rec* const r)
 
     // Store user info in the request
     const list<value> realm = assoc<value>("realm", info);
-    if(isNil(realm) || isNil(cdr(realm)))
+    if(isNull(realm) || isNull(cdr(realm)))
         return mkfailure<int>("Couldn't retrieve realm", HTTP_UNAUTHORIZED);
     apr_table_set(r->subprocess_env, apr_pstrdup(r->pool, "REALM"), apr_pstrdup(r->pool, c_str(cadr(realm))));
 
     const list<value> id = assoc<value>("id", info);
-    if(isNil(id) || isNil(cdr(id)))
+    if(isNull(id) || isNull(cdr(id)))
         return mkfailure<int>("Couldn't retrieve user id", HTTP_UNAUTHORIZED);
     r->user = apr_pstrdup(r->pool, c_str(cadr(id)));
 
@@ -313,7 +313,7 @@ static int checkAuthn(request_rec* const r) {
     }
 
     // Decline if the request is for another authentication provider
-    if(!isNil(assoc<value>("openid_identifier", args)))
+    if(!isNull(assoc<value>("openid_identifier", args)))
         return DECLINED;
 
     // Redirect to the login page, unless we have a session id from another module
diff --git a/sca-cpp/trunk/modules/http/openauth.hpp b/sca-cpp/trunk/modules/http/openauth.hpp
index 1c49c4254c..70c6f658ad 100644
--- a/sca-cpp/trunk/modules/http/openauth.hpp
+++ b/sca-cpp/trunk/modules/http/openauth.hpp
@@ -49,13 +49,13 @@ const char* const cookieName(const char* const cs) {
 }
 
 const maybe<string> sessionID(const list<string>& c, const string& key) {
-    if (isNil(c))
+    if (isNull(c))
         return maybe<string>();
     const string cn = cookieName(c_str(car(c)));
     const size_t i = find(cn, "=");
     if (i < length(cn)) {
         const list<string> kv = mklist<string>(substr(cn, 0, i), substr(cn, i+1));
-        if (!isNil(kv) && !isNil(cdr(kv))) {
+        if (!isNull(kv) && !isNull(cdr(kv))) {
             if (car(kv) == key)
                 return cadr(kv);
         }
@@ -92,10 +92,10 @@ const string cookie(const string& key, const string& sid, const string& domain)
  * Redirect to the configured login page.
  */
 const failable<int> login(const string& page, const value& ref, const value& attempt, request_rec* const r) {
-    const list<value> rarg = ref == string("/")? nilListValue : mklist<value>(mklist<value>("openauth_referrer", httpd::escape(httpd::url(isNil(ref)? r->uri : ref, r))));
-    const list<value> aarg = isNil(attempt)? nilListValue : mklist<value>(mklist<value>("openauth_attempt", attempt));
+    const list<value> rarg = ref == string("/")? nilListValue : mklist<value>(mklist<value>("openauth_referrer", httpd::escape(httpd::url(isNull(ref)? r->uri : ref, r))));
+    const list<value> aarg = isNull(attempt)? nilListValue : mklist<value>(mklist<value>("openauth_attempt", attempt));
     const list<value> largs = append(rarg, aarg);
-    const string loc = isNil(largs)? httpd::url(page, r) : httpd::url(page, r) + string("?") + http::queryString(largs);
+    const string loc = isNull(largs)? httpd::url(page, r) : httpd::url(page, r) + string("?") + http::queryString(largs);
     debug(loc, "openauth::login::uri");
     return httpd::externalRedirect(loc, r);
 }
diff --git a/sca-cpp/trunk/modules/java/driver.hpp b/sca-cpp/trunk/modules/java/driver.hpp
index 4ffc84f4db..a8d162249c 100644
--- a/sca-cpp/trunk/modules/java/driver.hpp
+++ b/sca-cpp/trunk/modules/java/driver.hpp
@@ -38,7 +38,7 @@ namespace java {
 const value evalDriverLoop(const JavaRuntime& jr, const JavaClass jc, istream& in, ostream& out) {
     scheme::promptForInput(scheme::evalInputPrompt, out);
     const value input = content(scheme::readValue(in));
-    if (isNil(input))
+    if (isNull(input))
         return input;
     const failable<value> output = evalClass(jr, input, jc);
     scheme::announceOutput(scheme::evalOutputPrompt, out);
diff --git a/sca-cpp/trunk/modules/java/eval.hpp b/sca-cpp/trunk/modules/java/eval.hpp
index 2c76b764fa..407e3d2a59 100644
--- a/sca-cpp/trunk/modules/java/eval.hpp
+++ b/sca-cpp/trunk/modules/java/eval.hpp
@@ -132,7 +132,7 @@ public:
         h.invokerLambda = h.env->GetFieldID(h.invokerClass, "lambda", "J");
         h.iterableUtilClass = h.env->FindClass("org/apache/tuscany/IterableUtil");
         h.iterableValueOf = h.env->GetStaticMethodID(h.iterableUtilClass, "list", "([Ljava/lang/Object;)Ljava/lang/Iterable;");
-        h.iterableIsNil = h.env->GetStaticMethodID(h.iterableUtilClass, "isNil", "(Ljava/lang/Object;)Z");
+        h.iterableIsNil = h.env->GetStaticMethodID(h.iterableUtilClass, "isNull", "(Ljava/lang/Object;)Z");
         h.iterableCar = h.env->GetStaticMethodID(h.iterableUtilClass, "car", "(Ljava/lang/Object;)Ljava/lang/Object;");
         h.iterableCdr = h.env->GetStaticMethodID(h.iterableUtilClass, "cdr", "(Ljava/lang/Object;)Ljava/lang/Iterable;");
         h.uuidClass = h.env->FindClass("org/apache/tuscany/UUIDUtil");
@@ -257,7 +257,7 @@ public:
     }
 
     const value operator()(const list<value>& expr) const {
-        if (isNil(expr))
+        if (isNull(expr))
             return func(expr);
         const value& op(car(expr));
         if (op == "equals")
@@ -331,7 +331,7 @@ const jobject mkJavaLambda(const JavaRuntime& jr, unused const value& iface, con
  * Convert a list of values to a Java jobjectArray.
  */
 const jobjectArray valuesToJarrayHelper(const JavaRuntime& jr, jobjectArray a, const list<value>& v, const int i) {
-    if (isNil(v))
+    if (isNull(v))
         return a;
     jr.h.env->SetObjectArrayElement(a, i, valueToJobject(jr, nilValue, car(v)));
     return valuesToJarrayHelper(jr, a, cdr(v), i + 1);
@@ -375,7 +375,7 @@ const jobject valueToJobject(const JavaRuntime& jr, const value& jtype, const va
  * Convert a list of values to an array of jvalues.
  */
 const jvalue* valuesToJvaluesHelper(const JavaRuntime& jr, jvalue* const a, const list<value>& types, const list<value>& v) {
-    if (isNil(v))
+    if (isNull(v))
         return a;
     a->l = valueToJobject(jr, car(types), car(v));
     return valuesToJvaluesHelper(jr, a + 1, cdr(types), cdr(v));
@@ -542,7 +542,7 @@ const failable<value> evalClass(const JavaRuntime& jr, const value& expr, const
 
     // Lookup the Java function named as the expression operand
     const list<value> func = assoc<value>(car<value>(expr), jc.m);
-    if (isNil(func)) {
+    if (isNull(func)) {
 
         // The start, stop, and restart functions are optional
         const value fn = car<value>(expr);
diff --git a/sca-cpp/trunk/modules/java/org/apache/tuscany/IterableUtil.java b/sca-cpp/trunk/modules/java/org/apache/tuscany/IterableUtil.java
index 2366d79af6..58bb18cf72 100644
--- a/sca-cpp/trunk/modules/java/org/apache/tuscany/IterableUtil.java
+++ b/sca-cpp/trunk/modules/java/org/apache/tuscany/IterableUtil.java
@@ -61,9 +61,9 @@ public class IterableUtil {
     /**
      * Return true if a list is nil (empty).
      */
-    public static boolean isNil(final Object l) {
+    public static boolean isNull(final Object l) {
         if(l instanceof BasicIterable<?>)
-            return ((BasicIterable<?>)l).isNil();
+            return ((BasicIterable<?>)l).isNull();
         if(l instanceof Collection<?>)
             return ((Collection<?>)l).isEmpty();
         return !((Iterable<?>)l).iterator().hasNext();
@@ -144,7 +144,7 @@ public class IterableUtil {
      */
     @SuppressWarnings("unchecked")
     public static <T> Iterable<T> append(final Object a, final Object b) {
-        if (isNil(a))
+        if (isNull(a))
             return (Iterable<T>)b;
         return cons(car(a), append(cdr(a), b));
     }
@@ -153,7 +153,7 @@ public class IterableUtil {
      * Return the first pair matching a key from a list of key value pairs.
      */
     public static <T> Iterable<T> assoc(final Object k, final Object l) {
-        if(isNil(l))
+        if(isNull(l))
             return list();
         if(k.equals(car(car(l))))
             return car(l);
@@ -168,11 +168,11 @@ public class IterableUtil {
 
         abstract Iterable<T> cdr();
 
-        abstract Boolean isNil();
+        abstract Boolean isNull();
 
         @Override
         public int size() {
-            return this.isNil()? 0 : 1 + ((List<T>)this.cdr()).size();
+            return this.isNull()? 0 : 1 + ((List<T>)this.cdr()).size();
         }
 
         @Override
@@ -194,7 +194,7 @@ public class IterableUtil {
         }
 
         @Override
-        Boolean isNil() {
+        Boolean isNull() {
             return this.a.length - this.start == 0;
         }
 
@@ -243,7 +243,7 @@ public class IterableUtil {
         }
 
         @Override
-        Boolean isNil() {
+        Boolean isNull() {
             return this.l.size() - this.start == 0;
         }
 
@@ -292,7 +292,7 @@ public class IterableUtil {
         }
 
         @Override
-        Boolean isNil() {
+        Boolean isNull() {
             return false;
         }
 
@@ -365,12 +365,12 @@ public class IterableUtil {
             assert jl.get(2) == Integer.valueOf(2);
 
             final Iterable<Object> n = list();
-            assert isNil(n);
+            assert isNull(n);
             assert n.toString().equals("[]");
 
             final Iterable<Object> cn = cons(0, n);
-            assert !isNil(cn);
-            assert isNil(cdr(cn));
+            assert !isNull(cn);
+            assert isNull(cdr(cn));
             assert cn.toString().equals("[0]");
 
             final Iterable<Object> al = new ArrayList<Object>(Arrays.asList(1, 2, 3));
diff --git a/sca-cpp/trunk/modules/java/test/ServerImpl.java b/sca-cpp/trunk/modules/java/test/ServerImpl.java
index 4499681f78..8a6f0e95c9 100644
--- a/sca-cpp/trunk/modules/java/test/ServerImpl.java
+++ b/sca-cpp/trunk/modules/java/test/ServerImpl.java
@@ -28,7 +28,7 @@ public class ServerImpl {
     }
 
     public Iterable<?> get(final Iterable<String> id) {
-        if (isNil(id))
+        if (isNull(id))
             return list(list("'feed", list("'title", "Sample Feed"), list("'id", "123456789"), list("'entry", list(
                     list(list("'title", "Item"), list("'id", "111"),
                         list("'content", list("'item", list("'name", "Apple"), list("'currencyCode", "USD"), list("'currencySymbol", "$"), list("'price", 2.99)))),
diff --git a/sca-cpp/trunk/modules/js/htdocs/atomutil.js b/sca-cpp/trunk/modules/js/htdocs/atomutil.js
index 3d4e9d08d2..4b57b36fb4 100644
--- a/sca-cpp/trunk/modules/js/htdocs/atomutil.js
+++ b/sca-cpp/trunk/modules/js/htdocs/atomutil.js
@@ -27,22 +27,22 @@ var atom = {};
  */
 atom.entryElementValues = function(e) {
     var lt = filter(selector(mklist(element, "'title")), e);
-    var t = mklist(element, "'title", isNil(lt)? '' : elementValue(car(lt)));
+    var t = mklist(element, "'title", isNull(lt)? '' : elementValue(car(lt)));
 
     var li = filter(selector(mklist(element, "'id")), e);
-    var i = mklist(element, "'id", isNil(li)? '' : elementValue(car(li)));
+    var i = mklist(element, "'id", isNull(li)? '' : elementValue(car(li)));
 
     var la = filter(selector(mklist(element, "'author")), e);
-    var lan = isNil(la)? mklist() : filter(selector(mklist(element, "'name")), car(la));
-    var lae = isNil(la)? mklist() : filter(selector(mklist(element, "'email")), car(la));
-    var laa = isNil(lan)? lae : lan;
-    var a = isNil(laa)? mklist() : mklist(mklist(element, "'author", elementValue(car(laa))));
+    var lan = isNull(la)? mklist() : filter(selector(mklist(element, "'name")), car(la));
+    var lae = isNull(la)? mklist() : filter(selector(mklist(element, "'email")), car(la));
+    var laa = isNull(lan)? lae : lan;
+    var a = isNull(laa)? mklist() : mklist(mklist(element, "'author", elementValue(car(laa))));
 
     var lu = filter(selector(mklist(element, "'updated")), e);
-    var u = isNil(lu)? mklist() : mklist(mklist(element, "'updated", elementValue(car(lu))));
+    var u = isNull(lu)? mklist() : mklist(mklist(element, "'updated", elementValue(car(lu))));
 
     var lc = filter(selector(mklist(element, "'content")), e);
-    var c = isNil(lc)? mklist() : isAttribute(elementValue(car(lc)))? mklist() : mklist(mklist(element, "'content", elementValue(car(lc))));
+    var c = isNull(lc)? mklist() : isAttribute(elementValue(car(lc)))? mklist() : mklist(mklist(element, "'content", elementValue(car(lc))));
 
     return append(append(append(mklist(element, "'entry", t, i), a), u), c);
 };
@@ -51,7 +51,7 @@ atom.entryElementValues = function(e) {
  * Convert a list of elements to a list of values representing ATOM entries.
  */
 atom.entriesElementValues = function(e) {
-    if (isNil(e))
+    if (isNull(e))
         return e;
     return cons(atom.entryElementValues(car(e)), atom.entriesElementValues(cdr(e)));
 };
@@ -70,7 +70,7 @@ atom.isATOMEntry = function(l) {
  */
 atom.readATOMEntryDocument = function(doc) {
     var e = readXMLDocument(doc);
-    if (isNil(e))
+    if (isNull(e))
         return mklist();
     return mklist(atom.entryElementValues(car(e)));
 };
@@ -96,7 +96,7 @@ atom.isATOMFeed = function(l) {
  */
 atom.readATOMFeedDocument = function(doc) {
     var f = readXMLDocument(doc);
-    if (isNil(f))
+    if (isNull(f))
         return mklist();
     var t = filter(selector(mklist(element, "'title")), car(f));
     var i = filter(selector(mklist(element, "'id")), car(f));
@@ -120,17 +120,17 @@ atom.entryElement = function(l) {
     var title = elementValue(namedElementChild("'title", l));
     var id = elementValue(namedElementChild("'id", l));
     var author = namedElementChild("'author", l);
-    var email = isNil(author)? false : (elementValue(author).indexOf('@') != -1);
+    var email = isNull(author)? false : (elementValue(author).indexOf('@') != -1);
     var updated = namedElementChild("'updated", l);
     var content = namedElementChild("'content", l);
-    var text = isNil(content)? false : elementHasValue(content);
+    var text = isNull(content)? false : elementHasValue(content);
     return append(append(append(append(
             mklist(element, "'entry", mklist(attribute, "'xmlns", "http://www.w3.org/2005/Atom"),
                 mklist(element, "'title", mklist(attribute, "'type", "text"), title), mklist(element, "'id", id)),
-                isNil(author)? mklist() : mklist(mklist(element, "'author",
+                isNull(author)? mklist() : mklist(mklist(element, "'author",
                     (email? mklist(element, "'email", elementValue(author)) : mklist(element, "'name", elementValue(author)))))),
-                isNil(updated)? mklist() : mklist(mklist(element, "'updated", elementValue(updated)))),
-                isNil(content)? mklist() :
+                isNull(updated)? mklist() : mklist(mklist(element, "'updated", elementValue(updated)))),
+                isNull(content)? mklist() :
                     mklist(append(mklist(element, "'content", mklist(attribute, "'type", text? "text" : "application/xml")),
                         text? mklist(elementValue(content)) : elementChildren(content)))),
                 mklist(mklist(element, "'link", mklist(attribute, "'href", id))));
@@ -140,7 +140,7 @@ atom.entryElement = function(l) {
  * Convert a list of values representing ATOM entries to a list of elements.
  */
 atom.entriesElements = function(l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons(atom.entryElement(car(l)), atom.entriesElements(cdr(l)));
 };
@@ -149,7 +149,7 @@ atom.entriesElements = function(l) {
  * Convert a list of values representing an ATOM entry to an ATOM entry.
  */
 atom.writeATOMEntry = function(ll) {
-    var l = isNil(ll)? ll : car(ll);
+    var l = isNull(ll)? ll : car(ll);
     return writeXML(mklist(atom.entryElement(l)), true);
 };
 
@@ -157,22 +157,22 @@ atom.writeATOMEntry = function(ll) {
  * Convert a list of values representing an ATOM feed to an ATOM feed.
  */
 atom.writeATOMFeed = function(ll) {
-    var l = isNil(ll)? ll : car(ll);
+    var l = isNull(ll)? ll : car(ll);
     var lt = filter(selector(mklist(element, "'title")), l);
-    var t = isNil(lt)? '' : elementValue(car(lt));
+    var t = isNull(lt)? '' : elementValue(car(lt));
     var li = filter(selector(mklist(element, "'id")), l);
-    var i = isNil(li)? '' : elementValue(car(li));
+    var i = isNull(li)? '' : elementValue(car(li));
     var f = mklist(element, "'feed", mklist(attribute, "'xmlns", "http://www.w3.org/2005/Atom"),
             mklist(element, "'title", mklist(attribute, "'type", "text"), car(l)),
             mklist(element, "'id", cadr(l)));
 
     // Write ATOM entries
     var le = filter(selector(mklist(element, "'entry")), l);
-    if (isNil(le))
+    if (isNull(le))
         return writeXML(mklist(f), true);
 
     // Write a single ATOM entry element with a list of values
-    if (!isNil(le) && !isNil(car(le)) && isList(car(caddr(car(le))))) {
+    if (!isNull(le) && !isNull(car(le)) && isList(car(caddr(car(le))))) {
         var fe = append(f, atom.entriesElements(caddr(car(le))));
         return writeXML(mklist(fe), true);
     }
diff --git a/sca-cpp/trunk/modules/js/htdocs/elemutil.js b/sca-cpp/trunk/modules/js/htdocs/elemutil.js
index 37d641f7b3..62050f5953 100644
--- a/sca-cpp/trunk/modules/js/htdocs/elemutil.js
+++ b/sca-cpp/trunk/modules/js/htdocs/elemutil.js
@@ -29,14 +29,14 @@ var atsign = "'@"
  * Return true if a value is an element.
  */
 function isElement(v) {
-    return (!(!isList(v) || isNil(v) || car(v) != element));
+    return (!(!isList(v) || isNull(v) || car(v) != element));
 }
 
 /**
  * Return true if a value is an attribute.
  */
 function isAttribute(v) {
-    return (!(!isList(v) || isNil(v) || car(v) != attribute));
+    return (!(!isList(v) || isNull(v) || car(v) != attribute));
 }
 
 /**
@@ -58,7 +58,7 @@ elementName = cadr;
  * Return true if an element has children.
  */
 function elementHasChildren(l) {
-    return !isNil(cddr(l));
+    return !isNull(cddr(l));
 }
 
 /**
@@ -73,7 +73,7 @@ function elementHasValue(l) {
     var r = reverse(l);
     if (isSymbol(car(r)))
         return false;
-    return (!(isList(car(r)) && !isNil(car(r)) && isSymbol(car(car(r)))))
+    return (!(isList(car(r)) && !isNull(car(r)) && isSymbol(car(car(r)))))
 }
 
 /**
@@ -89,7 +89,7 @@ function elementValue(l) {
 function elementToValueIsList(v) {
     if (!isList(v))
         return false;
-    return isNil(v) || !isSymbol(car(v));
+    return isNull(v) || !isSymbol(car(v));
 }
 
 function elementToValue(t) {
@@ -112,11 +112,11 @@ function elementToValue(t) {
  * Convert a list of elements to a list of values.
  */
 function elementToValueIsSymbol(v) {
-    return (!(!isList(v)) || isNil(v) || !isSymbol(car(v)));
+    return (!(!isList(v)) || isNull(v) || !isSymbol(car(v)));
 }
 
 function elementToValueGroupValues(v, l) {
-    if (isNil(l) || !elementToValueIsSymbol(v) || !elementToValueIsSymbol(car(l)))
+    if (isNull(l) || !elementToValueIsSymbol(v) || !elementToValueIsSymbol(car(l)))
         return cons(v, l);
     if (car(car(l)) != car(v))
         return cons(v, l);
@@ -129,7 +129,7 @@ function elementToValueGroupValues(v, l) {
 }
 
 function elementsToValues(e) {
-    if (isNil(e))
+    if (isNull(e))
         return e;
     return elementToValueGroupValues(elementToValue(car(e)), elementsToValues(cdr(e)));
 }
@@ -138,15 +138,15 @@ function elementsToValues(e) {
  * Convert a value to an element.
  */
 function valueToElement(t) {
-    if (isList(t) && !isNil(t) && isSymbol(car(t))) {
+    if (isList(t) && !isNull(t) && isSymbol(car(t))) {
         var n = car(t);
-        var v = isNil(cdr(t))? mklist() : cadr(t);
+        var v = isNull(cdr(t))? mklist() : cadr(t);
         if (!isList(v)) {
             if (n.substring(0, 2) == atsign)
                 return mklist(attribute, "'" + n.substring(2), v);
             return mklist(element, n, v);
         }
-        if (isNil(v) || !isSymbol(car(v)))
+        if (isNull(v) || !isSymbol(car(v)))
             return cons(element, cons(n, mklist(valuesToElements(v))));
         return cons(element, cons(n, valuesToElements(cdr(t))));
     }
@@ -159,7 +159,7 @@ function valueToElement(t) {
  * Convert a list of values to a list of elements.
  */
 function valuesToElements(l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons(valueToElement(car(l)), valuesToElements(cdr(l)));
 }
@@ -169,9 +169,9 @@ function valuesToElements(l) {
  */
 function selector(s) {
     function evalSelect(s, v) {
-        if (isNil(s))
+        if (isNull(s))
             return true;
-        if (isNil(v))
+        if (isNull(v))
             return false;
         if (car(s) != car(v))
             return false;
@@ -187,7 +187,7 @@ function selector(s) {
 function namedAttribute(name, l) {
     return memo(l, name, function() {
         var f = filter(function(v) { return isAttribute(v) && attributeName(v) == name; }, l);
-        if (isNil(f))
+        if (isNull(f))
             return null;
         return car(f);
     });
@@ -217,7 +217,7 @@ function namedElementChildren(name, l) {
  */
 function namedElementChild(name, l) {
     var f = namedElementChildren(name, l);
-    if (isNil(f))
+    if (isNull(f))
         return null;
     return car(f);
 }
diff --git a/sca-cpp/trunk/modules/js/htdocs/jsonutil.js b/sca-cpp/trunk/modules/js/htdocs/jsonutil.js
index 8aa291bc89..9960a5d82f 100644
--- a/sca-cpp/trunk/modules/js/htdocs/jsonutil.js
+++ b/sca-cpp/trunk/modules/js/htdocs/jsonutil.js
@@ -41,13 +41,13 @@ json.Exception.prototype.toString = function() {
  * Return true if a list represents a JS array.
  */
 json.isJSArray = function(l) {
-    if (isNil(l))
+    if (isNull(l))
         return true;
     var v = car(l);
     if (isSymbol(v))
         return false;
     if (isList(v))
-        if (!isNil(v) && isSymbol(car(v)))
+        if (!isNull(v) && isSymbol(car(v)))
             return false;
     return true;
 };
@@ -56,7 +56,7 @@ json.isJSArray = function(l) {
  * Converts JSON properties to values.
  */
 json.jsPropertiesToValues = function(propertiesSoFar, o, i) {
-    if (isNil(i))
+    if (isNull(i))
         return propertiesSoFar;
     var p = car(i);
     var jsv = o[p];
@@ -92,7 +92,7 @@ json.jsValToValue = function(jsv) {
  * Return true if a list of strings contains a JSON document.
  */
 json.isJSON = function(l) {
-    if (isNil(l))
+    if (isNull(l))
         return false;
     var s = car(l).slice(0, 1);
     return s == "[" || s == "{";
@@ -112,7 +112,7 @@ json.readJSON = function(l) {
  * Convert a list of values to JSON array elements.
  */
 json.valuesToJSElements = function(a, l, i) {
-    if (isNil(l))
+    if (isNull(l))
         return a;
     var pv = json.valueToJSVal(car(l));
     a[i] = pv
@@ -134,7 +134,7 @@ json.valueToJSVal = function(v) {
  * Convert a list of values to JSON properties.
  */
 json.valuesToJSProperties = function(o, l) {
-    if (isNil(l))
+    if (isNull(l))
         return o;
     var token = car(l);
     if (isTaggedList(token, attribute)) {
diff --git a/sca-cpp/trunk/modules/js/htdocs/scdl.js b/sca-cpp/trunk/modules/js/htdocs/scdl.js
index 50dab53e7c..fd0e08035f 100644
--- a/sca-cpp/trunk/modules/js/htdocs/scdl.js
+++ b/sca-cpp/trunk/modules/js/htdocs/scdl.js
@@ -27,7 +27,7 @@ var scdl = {};
  */
 scdl.composite = function(l) {
     var cs = namedElementChildren("'composite", l);
-    if (isNil(cs))
+    if (isNull(cs))
         return cs;
     return car(cs);
 };
@@ -37,7 +37,7 @@ scdl.composite = function(l) {
  */
 scdl.components = function(l) {
     var cs = namedElementChildren("'composite", l);
-    if (isNil(cs))
+    if (isNull(cs))
         return cs;
     return namedElementChildren("'component", car(cs));
 };
@@ -47,7 +47,7 @@ scdl.components = function(l) {
  */
 scdl.promotions = function(l) {
     var cs = namedElementChildren("'composite", l);
-    if (isNil(cs))
+    if (isNull(cs))
         return cs;
     return namedElementChildren("'service", car(cs));
 };
@@ -57,7 +57,7 @@ scdl.promotions = function(l) {
  */
 scdl.promote = function(l) {
     var puri = namedAttributeValue("'promote", l);
-    if (isNil(puri))
+    if (isNull(puri))
         return puri;
     return car(tokens(puri));
 };
@@ -74,7 +74,7 @@ scdl.name = function(l) {
  */
 scdl.documentation = function(l) {
     var d = namedElementChildren("'documentation", l);
-    if (isNil(d))
+    if (isNull(d))
         return null;
     if (!elementHasValue(car(d)))
         return null;
@@ -126,7 +126,7 @@ scdl.implementation = function(l) {
     }
 
     var n = filter(filterImplementation, l);
-    if (isNil(n))
+    if (isNull(n))
         return null;
     return car(n);
 };
@@ -204,21 +204,21 @@ scdl.bindingType = function(l) {
 scdl.target = function(l) {
     function targetURI() {
         function bindingsTarget(l) {
-            if (isNil(l))
+            if (isNull(l))
                 return null;
             var u = scdl.uri(car(l));
-            if (!isNil(u))
+            if (!isNull(u))
                 return u;
             return bindingsTarget(cdr(l));
         }
     
         var t = namedAttributeValue("'target", l);
-        if (!isNil(t))
+        if (!isNull(t))
             return t;
         return bindingsTarget(scdl.bindings(l));
     }
     var turi = targetURI();
-    if (isNil(turi))
+    if (isNull(turi))
         return turi;
     return car(tokens(turi));
 };
@@ -243,7 +243,7 @@ scdl.propertyValue = function(l) {
  * Convert a list of elements to a name -> element assoc list.
  */
 scdl.nameToElementAssoc = function(l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons(mklist(scdl.name(car(l)), car(l)), scdl.nameToElementAssoc(cdr(l)));
 };
diff --git a/sca-cpp/trunk/modules/js/htdocs/ui.js b/sca-cpp/trunk/modules/js/htdocs/ui.js
index 0c80b92bcf..3aa9e1052a 100644
--- a/sca-cpp/trunk/modules/js/htdocs/ui.js
+++ b/sca-cpp/trunk/modules/js/htdocs/ui.js
@@ -31,7 +31,7 @@ ui.elementByID = function(node, id) {
         return null;
     for (var i in node.childNodes) {
         var child = node.childNodes[i];
-        if (isNil(child))
+        if (isNull(child))
             continue;
         if (child.id == id)
             return child;
@@ -275,7 +275,7 @@ ui.msieVersion = function() {
  */
 ui.asyncFrame = null;
 ui.async = function(f) {
-    if (isNil(ui.asyncFrame))
+    if (isNull(ui.asyncFrame))
         // Use requestAnimationFrame when available, fallback to setTimeout
         ui.asyncFrame = window.requestAnimationFrame || window.webkitRequestAnimationFrame ||
             window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
@@ -293,7 +293,7 @@ ui.delay = function(f, t) {
     var id =  window.setTimeout(function() {
         delete ui.delayed[id];
         return f();
-    }, isNil(t)? 16 : t);
+    }, isNull(t)? 16 : t);
     ui.delayed[id] = id;
     return id;
 };
@@ -311,12 +311,12 @@ ui.cancelDelay = function(id) {
  */
 ui.animationFrame = null;
 ui.animation = function(f) {
-    if (isNil(ui.animationFrame))
+    if (isNull(ui.animationFrame))
         // Use requestAnimationFrame when available, fallback to setInterval
         ui.animationFrame = window.requestAnimationFrame || window.webkitRequestAnimationFrame ||
             window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
             function(f) {
-                if (!('interval' in f) || isNil(f.interval)) {
+                if (!('interval' in f) || isNull(f.interval)) {
                     // First call, setup the interval
                     f.interval = window.setInterval(function animation() {
                         f.clearInterval = true;
@@ -370,7 +370,7 @@ ui.onload = function() {
     } else {
         // Style scroll bars
         var h = document.getElementsByTagName('html');
-        if (!isNil(h))
+        if (!isNull(h))
             h[0].className = h[0].className? h[0].classname + ' flatscrollbars' : 'flatscrollbars';
     }
 
@@ -393,7 +393,7 @@ ui.onload = function() {
 ui.onorientationchange = function(e) {
 
     // Adjust filler height
-    if (!isNil(ui.filler))
+    if (!isNull(ui.filler))
         ui.filler.style.height = ui.pixpos(window.orientation == 0? screen.height : screen.width);
 
     // Scroll to hide the address bar
@@ -524,7 +524,7 @@ ui.datatable = function(l) {
     }
 
     function rows(l, i) {
-        if (isNil(l))
+        if (isNull(l))
             return '';
         var e = car(l);
 
@@ -564,7 +564,7 @@ ui.datatable = function(l) {
 ui.datalist = function(l) {
 
     function rows(l, i) {
-        if (isNil(l))
+        if (isNull(l))
             return '';
         var e = car(l);
 
diff --git a/sca-cpp/trunk/modules/js/htdocs/util.js b/sca-cpp/trunk/modules/js/htdocs/util.js
index 1cf086c60e..a8fec3994d 100644
--- a/sca-cpp/trunk/modules/js/htdocs/util.js
+++ b/sca-cpp/trunk/modules/js/htdocs/util.js
@@ -81,7 +81,7 @@ function range(a, b) {
     return l;
 }
 
-function isNil(v) {
+function isNull(v) {
     return (v == null || typeof v == 'undefined' || (v.constructor == Array && v.length == 0));
 }
 
@@ -98,7 +98,7 @@ function isList(v) {
 }
 
 function isTaggedList(v, t) {
-    return (isList(v) && !isNil(v) && car(v) == t);
+    return (isList(v) && !isNull(v) && car(v) == t);
 }
 
 var emptylist = new Array();
@@ -120,7 +120,7 @@ function length(l) {
  * Scheme-like associations.
  */
 function assoc(k, l) {
-    if (isNil(l))
+    if (isNull(l))
         return emptylist;
     var n = l.length;
     for(var i = 0; i < n; i++) {
@@ -134,7 +134,7 @@ function assoc(k, l) {
  * Map, filter and reduce functions.
  */
 function map(f, l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     var n = l.length;
     var a = new Array();
@@ -145,7 +145,7 @@ function map(f, l) {
 }
 
 function filter(f, l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     var n = l.length;
     var a = new Array();
@@ -157,7 +157,7 @@ function filter(f, l) {
 }
 
 function reduce(f, i, l) {
-    if (isNil(l))
+    if (isNull(l))
         return i;
     return reduce(f, f(i, car(l)), cdr(l));
 }
@@ -223,7 +223,7 @@ function isIE() {
  * External build configuration.
  */
 var config;
-if (isNil(config))
+if (isNull(config))
     config = {};
 
 /**
@@ -245,7 +245,7 @@ function assert(exp) {
  * Write a list of strings.
  */
 function writeStrings(l) {
-    if (isNil(l))
+    if (isNull(l))
         return '';
     var s = '';
     var n = l.length;
@@ -268,14 +268,14 @@ function writeValue(v) {
     }
 
     function writeList(l) {
-        if (isNil(l))
+        if (isNull(l))
             return '';
         return ' ' + writeValue(car(l)) + writeList(cdr(l));
     }
 
     if (!isList(v))
         return writePrimitive(v);
-    if (isNil(v))
+    if (isNull(v))
         return '()';
     return '(' + writeValue(car(v)) + writeList(cdr(v)) + ')';
 }
@@ -403,7 +403,7 @@ function domainname(host) {
     if (s != -1)
         return domainname(host.substring(0, s));
     var h = reverse(host.split('.'));
-    var d = (!isNil(cddr(h)) && caddr(h) == 'www')? mklist(car(h), cadr(h), caddr(h)) : mklist(car(h), cadr(h));
+    var d = (!isNull(cddr(h)) && caddr(h) == 'www')? mklist(car(h), cadr(h), caddr(h)) : mklist(car(h), cadr(h));
     return reverse(d).join('.');
 }
 
@@ -536,7 +536,7 @@ function setcaddr(l, v) {
  * Append the elements of a list to a list.
  */
 function setappend(a, b) {
-    if (isNil(b))
+    if (isNull(b))
         return a;
     a.push(car(b));
     return setappend(a, cdr(b));
diff --git a/sca-cpp/trunk/modules/js/htdocs/xmlutil.js b/sca-cpp/trunk/modules/js/htdocs/xmlutil.js
index 4d943cce75..29240dff9c 100644
--- a/sca-cpp/trunk/modules/js/htdocs/xmlutil.js
+++ b/sca-cpp/trunk/modules/js/htdocs/xmlutil.js
@@ -26,7 +26,7 @@
  */
 function nodeList(n) {
     var l = new Array();
-    if (isNil(n))
+    if (isNull(n))
         return l;
     for (var i = 0; i < n.length; i++)
         l[i] = n[i];
@@ -37,7 +37,7 @@ function nodeList(n) {
  * Append a list of nodes to a parent node.
  */
 function appendNodes(nodes, p) {
-    if (isNil(nodes))
+    if (isNull(nodes))
         return p;
     p.appendChild(car(nodes));
     return appendNodes(cdr(nodes), p);
@@ -71,7 +71,7 @@ function childText(e) {
  * Read a list of XML attributes.
  */
 function readAttributes(p, a) {
-    if (isNil(a))
+    if (isNull(a))
         return a;
     var x = car(a);
     return cons(mklist(attribute, "'" + x.nodeName, x.nodeValue), readAttributes(p, cdr(a)));
@@ -83,7 +83,7 @@ function readAttributes(p, a) {
 function readElement(e, childf) {
     var l = append(append(mklist(element, "'" + e.nodeName), readAttributes(e, childf(e))), readElements(childElements(e), childf));
     var t = childText(e);
-    if (isNil(t))
+    if (isNull(t))
         return l;
     return append(l, mklist(car(t).nodeValue));
 }
@@ -92,7 +92,7 @@ function readElement(e, childf) {
  * Read a list of XML elements.
  */
 function readElements(l, childf) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons(readElement(car(l), childf), readElements(cdr(l), childf));
 }
@@ -101,7 +101,7 @@ function readElements(l, childf) {
  * Return true if a list of strings contains an XML document.
  */
 function isXML(l) {
-    if (isNil(l))
+    if (isNull(l))
         return false;
     return car(l).substring(0, 5) == '<?xml';
 }
@@ -120,7 +120,7 @@ function parseXML(l) {
  */
 function readXMLDocument(doc) {
     var root = childElements(doc);
-    if (isNil(root))
+    if (isNull(root))
         return mklist();
     return mklist(readElement(car(root), childAttributes));
 }
@@ -133,7 +133,7 @@ function readXHTMLElement(xhtml) {
     function ieChildAttributes(e) {
         var a = filter(function(n) {
             // Filter out empty and internal DOM attributes
-            if (n.nodeType != 2 || isNil(n.nodeValue) || n.nodeValue == '')
+            if (n.nodeType != 2 || isNull(n.nodeValue) || n.nodeValue == '')
                 return false;
             if (n.nodeName == 'contentEditable' || n.nodeName == 'maxLength' || n.nodeName == 'loop' || n.nodeName == 'start')
                 return false;
@@ -174,13 +174,13 @@ function writeXMLDocument(doc) {
  * Write a list of XML element and attribute tokens.
  */
 function expandElementValues(n, l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons(cons(element, cons(n, car(l))), expandElementValues(n, cdr(l)));
 }
 
 function writeList(l, node, doc) {
-    if (isNil(l))
+    if (isNull(l))
         return node;
 
     var token = car(l);
@@ -196,7 +196,7 @@ function writeList(l, node, doc) {
 
         function mkelem(tok, doc) {
             function xmlns(l) {
-                if (isNil(l))
+                if (isNull(l))
                     return null;
                 var t = car(l);
                 if (isTaggedList(t, attribute)) {
diff --git a/sca-cpp/trunk/modules/json/json.hpp b/sca-cpp/trunk/modules/json/json.hpp
index 497624070b..caef19b835 100644
--- a/sca-cpp/trunk/modules/json/json.hpp
+++ b/sca-cpp/trunk/modules/json/json.hpp
@@ -58,13 +58,13 @@ public:
  * Returns true if a list represents a JS array.
  */
 inline const bool isJSArray(const list<value>& l) {
-    if(isNil(l))
+    if(isNull(l))
         return true;
     const value v = car(l);
     if (isSymbol(v))
         return false;
     if(isList(v)) {
-        if(!isNil((list<value>)v) && isSymbol(car<value>(v)))
+        if(!isNull((list<value>)v) && isSymbol(car<value>(v)))
             return false;
     }
     return true;
@@ -94,7 +94,7 @@ inline const list<value> jsPropertiesToValues(const list<value>& propertiesSoFar
     const char* const name = json_object_iter_key(i);
     json_t* const jsv = json_object_iter_value(i);
     const value val = jsValToValue(jsv);
-    if (isNil(val) && !isList(val))
+    if (isNull(val) && !isList(val))
         return jsPropertiesToValues(cons<value> (mklist<value> (element, c_str(name), val), propertiesSoFar), o, json_object_iter_next(o, i));
     if (substr(name, 0, 1) == atsign)
         return jsPropertiesToValues(cons<value>(mklist<value>(attribute, c_str(substr(name, 1)), val), propertiesSoFar), o, json_object_iter_next(o, i));
@@ -148,7 +148,7 @@ const value jsValToValue(json_t* const jsv) {
  */
 inline json_t* const valuesToJSElements(json_t* const a, const list<value>& l) {
     json_t* const valueToJSVal(const value& val);
-    if (isNil(l))
+    if (isNull(l))
         return a;
     json_t* const v = valueToJSVal(car(l));
     json_array_append(a, v);
@@ -199,7 +199,7 @@ inline json_t* const valueToJSVal(const value& val) {
  * Converts a list of values to JS properties.
  */
 inline json_t* const valuesToJSProperties(json_t* const o, const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return o;
 
     // Write an attribute
@@ -235,7 +235,7 @@ inline json_t* const valuesToJSProperties(json_t* const o, const list<value>& l)
  * Return true if a list of strings contains a JSON document.
  */
 inline const bool isJSON(const list<string>& ls) {
-    if (isNil(ls))
+    if (isNull(ls))
         return false;
     const string s = substr(car(ls), 0, 1);
     return s == "[" || s == "{";
@@ -390,7 +390,7 @@ inline const string funcName(const string& f) {
  * of key value pairs.
  */
 inline const list<value> queryParams(const list<value>& a) {
-    if (isNil(a))
+    if (isNull(a))
         return nilListValue;
     const list<value> p = car(a);
     if (car(p) == value("id") || car(p) == value("method"))
diff --git a/sca-cpp/trunk/modules/oauth/mod-oauth1.cpp b/sca-cpp/trunk/modules/oauth/mod-oauth1.cpp
index a7238804f8..b1786d1098 100644
--- a/sca-cpp/trunk/modules/oauth/mod-oauth1.cpp
+++ b/sca-cpp/trunk/modules/oauth/mod-oauth1.cpp
@@ -104,7 +104,7 @@ public:
  * Run the authnz hooks to authenticate a request.
  */
 const failable<int> checkAuthnzProviders(const string& user, request_rec* const r, const list<AuthnProviderConf>& apcs) {
-    if (isNil(apcs))
+    if (isNull(apcs))
         return mkfailure<int>("Authentication failure for: " + user, HTTP_UNAUTHORIZED);
     const AuthnProviderConf apc = car<AuthnProviderConf>(apcs);
     if (apc.provider == NULL || !apc.provider->check_password)
@@ -122,7 +122,7 @@ const failable<int> checkAuthnz(const string& user, request_rec* const r, const
     if (substr(user, 0, 1) == "/")
         return mkfailure<int>(string("Encountered FakeBasicAuth spoof: ") + user, HTTP_UNAUTHORIZED);
 
-    if (isNil(apcs)) {
+    if (isNull(apcs)) {
         const authn_provider* provider = (const authn_provider*)ap_lookup_provider(AUTHN_PROVIDER_GROUP, AUTHN_DEFAULT_PROVIDER, AUTHN_PROVIDER_VERSION);
         return checkAuthnzProviders(user, r, mklist<AuthnProviderConf>(AuthnProviderConf(AUTHN_DEFAULT_PROVIDER, provider)));
     }
@@ -142,11 +142,11 @@ const failable<value> userInfo(const value& sid, const memcache::MemCached& mc)
 const failable<int> authenticated(const list<value>& userinfo, const bool check, request_rec* const r, const list<value>& scopeattrs, const list<AuthnProviderConf>& apcs) {
     debug(userinfo, "modoauth2::authenticated::userinfo");
 
-    if (isNil(scopeattrs)) {
+    if (isNull(scopeattrs)) {
 
         // Store user id in an environment variable
         const list<value> id = assoc<value>("id", userinfo);
-        if (isNil(id) || isNil(cdr(id)))
+        if (isNull(id) || isNull(cdr(id)))
             return mkfailure<int>("Couldn't retrieve user id", HTTP_UNAUTHORIZED);
         apr_table_set(r->subprocess_env, "OAUTH2_ID", apr_pstrdup(r->pool, c_str(cadr(id))));
 
@@ -164,7 +164,7 @@ const failable<int> authenticated(const list<value>& userinfo, const bool check,
     // Store each configured OAuth scope attribute in an environment variable
     const list<value> a = car(scopeattrs);
     const list<value> v = assoc<value>(cadr(a), userinfo);
-    if (!isNil(v) && !isNil(cdr(v))) {
+    if (!isNull(v) && !isNull(cdr(v))) {
 
         // Map the REMOTE_USER attribute to the request user field
         if (string(car(a)) == "REMOTE_USER")
@@ -192,7 +192,7 @@ const string header(const string& qs, const string& redir, const string& verif)
         << "oauth_consumer_key=\"" << string(cadr(assoc<value>("oauth_consumer_key", args))) << "\", ";
 
     const list<value> atok = assoc<value>("oauth_token", args);
-    if (!isNil(atok) && !isNil(cdr(atok)))
+    if (!isNull(atok) && !isNull(cdr(atok)))
         hdr << "oauth_token=\"" << string(cadr(atok)) << "\", ";
 
     if (length(verif) != 0)
@@ -223,22 +223,22 @@ const list<string> sign(const string& verb, const string& uri, const list<value>
 const failable<int> authorize(const list<value>& args, request_rec* const r, const list<value>& appkeys, const memcache::MemCached& mc) {
     // Extract authorize, access_token, client ID and info URIs
     const list<value> ref = assoc<value>("openauth_referrer", args);
-    if (isNil(ref) || isNil(cdr(ref)))
+    if (isNull(ref) || isNull(cdr(ref)))
         return mkfailure<int>("Missing openauth_referrer parameter");
     const list<value> req = assoc<value>("oauth1_request_token", args);
-    if (isNil(req) || isNil(cdr(req)))
+    if (isNull(req) || isNull(cdr(req)))
         return mkfailure<int>("Missing oauth1_request_token parameter");
     const list<value> auth = assoc<value>("oauth1_authorize", args);
-    if (isNil(auth) || isNil(cdr(auth)))
+    if (isNull(auth) || isNull(cdr(auth)))
         return mkfailure<int>("Missing oauth1_authorize parameter");
     const list<value> tok = assoc<value>("oauth1_access_token", args);
-    if (isNil(tok) || isNil(cdr(tok)))
+    if (isNull(tok) || isNull(cdr(tok)))
         return mkfailure<int>("Missing oauth1_access_token parameter");
     const list<value> cid = assoc<value>("oauth1_client_id", args);
-    if (isNil(cid) || isNil(cdr(cid)))
+    if (isNull(cid) || isNull(cdr(cid)))
         return mkfailure<int>("Missing oauth1_client_id parameter");
     const list<value> info = assoc<value>("oauth1_info", args);
-    if (isNil(info) || isNil(cdr(info)))
+    if (isNull(info) || isNull(cdr(info)))
         return mkfailure<int>("Missing oauth1_info parameter");
 
     // Build the redirect URI
@@ -248,7 +248,7 @@ const failable<int> authorize(const list<value>& args, request_rec* const r, con
 
     // Lookup client app configuration
     const list<value> app = assoc<value>(cadr(cid), appkeys);
-    if (isNil(app) || isNil(cdr(app)))
+    if (isNull(app) || isNull(cdr(app)))
         return mkfailure<int>(string("client id not found: ") + (string)cadr(cid));
     list<value> appkey = cadr(app);
 
@@ -271,13 +271,13 @@ const failable<int> authorize(const list<value>& args, request_rec* const r, con
 
     // Retrieve the request token
     const list<value> conf = assoc<value>("oauth_callback_confirmed", resargs);
-    if (isNil(conf) || isNil(cdr(conf)) || cadr(conf) != "true")
+    if (isNull(conf) || isNull(cdr(conf)) || cadr(conf) != "true")
         return mkfailure<int>("Couldn't confirm oauth_callback");
     const list<value> tv = assoc<value>("oauth_token", resargs);
-    if (isNil(tv) || isNil(cdr(tv)))
+    if (isNull(tv) || isNull(cdr(tv)))
         return mkfailure<int>("Couldn't retrieve oauth_token");
     const list<value> sv = assoc<value>("oauth_token_secret", resargs);
-    if (isNil(sv) || isNil(cdr(sv)))
+    if (isNull(sv) || isNull(cdr(sv)))
         return mkfailure<int>("Couldn't retrieve oauth_token_secret");
 
     // Store the request token in memcached
@@ -301,12 +301,12 @@ const failable<list<value> > profileUserInfo(const value& cid, const string& inf
     if (b == "[") {
         // Twitter JSON profile
         const list<value> infov(content(json::readValue(mklist<string>(info))));
-        if (isNil(infov))
+        if (isNull(infov))
             return mkfailure<list<value> >("Couldn't retrieve user info");
         debug(infov, "modoauth1::access_token::info");
         const list<value> uv = assoc<value>("user", car(infov));
         debug(uv, "modoauth1::access_token::userInfo");
-        if (isNil(uv) || isNil(cdr(uv)))
+        if (isNull(uv) || isNull(cdr(uv)))
             return mkfailure<list<value> >("Couldn't retrieve user info");
         const list<value> iv = cdr(uv);
         return cons<value>(mklist<value>("realm", cid), iv);
@@ -314,12 +314,12 @@ const failable<list<value> > profileUserInfo(const value& cid, const string& inf
     if (b == "{") {
         // Foursquare JSON profile
         const list<value> infov(content(json::readValue(mklist<string>(info))));
-        if (isNil(infov))
+        if (isNull(infov))
             return mkfailure<list<value> >("Couldn't retrieve user info");
         debug(infov, "modoauth1::access_token::info");
         const list<value> uv = assoc<value>("user", infov);
         debug(uv, "modoauth1::access_token::userInfo");
-        if (isNil(uv) || isNil(cdr(uv)))
+        if (isNull(uv) || isNull(cdr(uv)))
             return mkfailure<list<value> >("Couldn't retrieve user info");
         const list<value> iv = cdr(uv);
         return cons<value>(mklist<value>("realm", cid), iv);
@@ -327,12 +327,12 @@ const failable<list<value> > profileUserInfo(const value& cid, const string& inf
     if (b == "<") {
         // XML profile
         const list<value> infov = elementsToValues(content(xml::readElements(mklist<string>(info))));
-        if (isNil(infov))
+        if (isNull(infov))
             return mkfailure<list<value> >("Couldn't retrieve user info");
         debug(infov, "modoauth1::access_token::info");
         const list<value> pv = car(infov);
         debug(pv, "modoauth1::access_token::userInfo");
-        if (isNil(pv) || isNil(cdr(pv)))
+        if (isNull(pv) || isNull(cdr(pv)))
             return mkfailure<list<value> >("Couldn't retrieve user info");
         const list<value> iv = cdr(pv);
         return cons<value>(mklist<value>("realm", cid), iv);
@@ -347,27 +347,27 @@ const failable<int> accessToken(const list<value>& args, request_rec* r, const l
 
     // Extract access_token URI, client ID and verification code
     const list<value> ref = assoc<value>("openauth_referrer", args);
-    if (isNil(ref) || isNil(cdr(ref)))
+    if (isNull(ref) || isNull(cdr(ref)))
         return mkfailure<int>("Missing openauth_referrer parameter");
     const list<value> tok = assoc<value>("oauth1_access_token", args);
-    if (isNil(tok) || isNil(cdr(tok)))
+    if (isNull(tok) || isNull(cdr(tok)))
         return mkfailure<int>("Missing oauth1_access_token parameter");
     const list<value> cid = assoc<value>("oauth1_client_id", args);
-    if (isNil(cid) || isNil(cdr(cid)))
+    if (isNull(cid) || isNull(cdr(cid)))
         return mkfailure<int>("Missing oauth1_client_id parameter");
     const list<value> info = assoc<value>("oauth1_info", args);
-    if (isNil(info) || isNil(cdr(info)))
+    if (isNull(info) || isNull(cdr(info)))
         return mkfailure<int>("Missing oauth1_info parameter");
     const list<value> tv = assoc<value>("oauth_token", args);
-    if (isNil(tv) || isNil(cdr(tv)))
+    if (isNull(tv) || isNull(cdr(tv)))
         return mkfailure<int>("Missing oauth_token parameter");
     const list<value> vv = assoc<value>("oauth_verifier", args);
-    if (isNil(vv) || isNil(cdr(vv)))
+    if (isNull(vv) || isNull(cdr(vv)))
         return mkfailure<int>("Missing oauth_verifier parameter");
 
     // Lookup client app configuration
     const list<value> app = assoc<value>(cadr(cid), appkeys);
-    if (isNil(app) || isNil(cdr(app)))
+    if (isNull(app) || isNull(cdr(app)))
         return mkfailure<int>(string("client id not found: ") + (string)cadr(cid));
     const list<value> appkey = cadr(app);
 
@@ -395,10 +395,10 @@ const failable<int> accessToken(const list<value>& args, request_rec* r, const l
 
     // Retrieve the access token
     const list<value> atv = assoc<value>("oauth_token", tokresargs);
-    if (isNil(atv) || isNil(cdr(atv)))
+    if (isNull(atv) || isNull(cdr(atv)))
         return mkfailure<int>("Couldn't retrieve oauth_token");
     const list<value> asv = assoc<value>("oauth_token_secret", tokresargs);
-    if (isNil(asv) || isNil(cdr(asv)))
+    if (isNull(asv) || isNull(cdr(asv)))
         return mkfailure<int>("Couldn't retrieve oauth_token_secret");
     debug(atv, "modoauth1::access_token::token");
 
@@ -498,7 +498,7 @@ static int checkAuthn(request_rec *r) {
         hasContent(openauth::sessionID(r, "TuscanyOpenAuth")) ||
         hasContent(openauth::sessionID(r, "TuscanyOAuth2")))
         return DECLINED;
-    if ((substr(string(r->uri), 0, 8) == "/oauth2/") || !isNil(assoc<value>("openid_identifier", args)))
+    if ((substr(string(r->uri), 0, 8) == "/oauth2/") || !isNull(assoc<value>("openid_identifier", args)))
         return DECLINED;
 
     r->ap_auth_type = const_cast<char*>(atype);
@@ -515,9 +515,9 @@ int postConfigMerge(const ServerConf& mainsc, server_rec* const s) {
     debug(httpd::serverName(s), "modoauth1::postConfigMerge::serverName");
 
     // Merge configuration from main server
-    if (isNil((list<value>)sc.appkeys))
+    if (isNull((list<value>)sc.appkeys))
         sc.appkeys = mainsc.appkeys;
-    if (isNil((list<string>)sc.mcaddrs))
+    if (isNull((list<string>)sc.mcaddrs))
         sc.mcaddrs = mainsc.mcaddrs;
     sc.mc = mainsc.mc;
     sc.cs = mainsc.cs;
@@ -549,7 +549,7 @@ void childInit(apr_pool_t* const p, server_rec* const s) {
     ServerConf& sc = *psc;
 
     // Connect to Memcached
-    if (isNil((list<string>)sc.mcaddrs))
+    if (isNull((list<string>)sc.mcaddrs))
         sc.mc = *(new (gc_new<memcache::MemCached>()) memcache::MemCached("localhost", 11211));
     else
         sc.mc = *(new (gc_new<memcache::MemCached>()) memcache::MemCached(sc.mcaddrs));
diff --git a/sca-cpp/trunk/modules/oauth/mod-oauth2.cpp b/sca-cpp/trunk/modules/oauth/mod-oauth2.cpp
index 5bc212a681..0a4405ce2e 100644
--- a/sca-cpp/trunk/modules/oauth/mod-oauth2.cpp
+++ b/sca-cpp/trunk/modules/oauth/mod-oauth2.cpp
@@ -98,7 +98,7 @@ public:
  * Run the authnz hooks to authenticate a request.
  */
 const failable<int> checkAuthnzProviders(const string& user, request_rec* const r, const list<AuthnProviderConf>& apcs) {
-    if (isNil(apcs))
+    if (isNull(apcs))
         return mkfailure<int>("Authentication failure for: " + user, HTTP_UNAUTHORIZED);
     const AuthnProviderConf apc = car<AuthnProviderConf>(apcs);
     if (apc.provider == NULL || !apc.provider->check_password)
@@ -116,7 +116,7 @@ const failable<int> checkAuthnz(const string& user, request_rec* const r, const
     if (substr(user, 0, 1) == "/")
         return mkfailure<int>(string("Encountered FakeBasicAuth spoof: ") + user, HTTP_UNAUTHORIZED);
 
-    if (isNil(apcs)) {
+    if (isNull(apcs)) {
         const authn_provider* provider = (const authn_provider*)ap_lookup_provider(AUTHN_PROVIDER_GROUP, AUTHN_DEFAULT_PROVIDER, AUTHN_PROVIDER_VERSION);
         return checkAuthnzProviders(user, r, mklist<AuthnProviderConf>(AuthnProviderConf(AUTHN_DEFAULT_PROVIDER, provider)));
     }
@@ -136,11 +136,11 @@ const failable<value> userInfo(const value& sid, const memcache::MemCached& mc)
 const failable<int> authenticated(const list<value>& userinfo, const bool check, request_rec* const r, const list<value>& scopeattrs, const list<AuthnProviderConf>& apcs) {
     debug(userinfo, "modoauth2::authenticated::userinfo");
 
-    if (isNil(scopeattrs)) {
+    if (isNull(scopeattrs)) {
 
         // Store user id in an environment variable
         const list<value> id = assoc<value>("id", userinfo);
-        if (isNil(id) || isNil(cdr(id)))
+        if (isNull(id) || isNull(cdr(id)))
             return mkfailure<int>("Couldn't retrieve user id", HTTP_UNAUTHORIZED);
         apr_table_set(r->subprocess_env, "OAUTH2_ID", apr_pstrdup(r->pool, c_str(cadr(id))));
 
@@ -158,7 +158,7 @@ const failable<int> authenticated(const list<value>& userinfo, const bool check,
     // Store each configured OAuth scope attribute in an environment variable
     const list<value> a = car(scopeattrs);
     const list<value> v = assoc<value>(cadr(a), userinfo);
-    if (!isNil(v) && !isNil(cdr(v))) {
+    if (!isNull(v) && !isNull(cdr(v))) {
 
         // Map the REMOTE_USER attribute to the request user field
         if (string(car(a)) == "REMOTE_USER")
@@ -175,22 +175,22 @@ const failable<int> authenticated(const list<value>& userinfo, const bool check,
 const failable<int> authorize(const list<value>& args, request_rec* const r, const list<value>& appkeys) {
     // Extract authorize, access_token, client ID and info URIs
     const list<value> ref = assoc<value>("openauth_referrer", args);
-    if (isNil(ref) || isNil(cdr(ref)))
+    if (isNull(ref) || isNull(cdr(ref)))
         return mkfailure<int>("Missing openauth_referrer parameter");
     const list<value> auth = assoc<value>("oauth2_authorize", args);
-    if (isNil(auth) || isNil(cdr(auth)))
+    if (isNull(auth) || isNull(cdr(auth)))
         return mkfailure<int>("Missing oauth2_authorize parameter");
     const list<value> tok = assoc<value>("oauth2_access_token", args);
-    if (isNil(tok) || isNil(cdr(tok)))
+    if (isNull(tok) || isNull(cdr(tok)))
         return mkfailure<int>("Missing oauth2_access_token parameter");
     const list<value> cid = assoc<value>("oauth2_client_id", args);
-    if (isNil(cid) || isNil(cdr(cid)))
+    if (isNull(cid) || isNull(cdr(cid)))
         return mkfailure<int>("Missing oauth2_client_id parameter");
     const list<value> info = assoc<value>("oauth2_info", args);
-    if (isNil(info) || isNil(cdr(info)))
+    if (isNull(info) || isNull(cdr(info)))
         return mkfailure<int>("Missing oauth2_info parameter");
     const list<value> scope = assoc<value>("oauth2_scope", args);
-    if (isNil(scope) || isNil(cdr(scope)))
+    if (isNull(scope) || isNull(cdr(scope)))
         return mkfailure<int>("Missing oauth2_scope parameter");
     const list<value> display = assoc<value>("oauth2_display", args);
 
@@ -205,12 +205,12 @@ const failable<int> authorize(const list<value>& args, request_rec* const r, con
 
     // Lookup client app configuration
     const list<value> app = assoc<value>(cadr(cid), appkeys);
-    if (isNil(app) || isNil(cdr(app)))
+    if (isNull(app) || isNull(cdr(app)))
         return mkfailure<int>(string("client id not found: ") + (string)cadr(cid));
     list<value> appkey = cadr(app);
 
     // Redirect to the authorize URI
-    const list<value> adisplay = (isNil(display) || isNil(cdr(display)))? nilListValue : mklist<value>("display", cadr(display));
+    const list<value> adisplay = (isNull(display) || isNull(cdr(display)))? nilListValue : mklist<value>("display", cadr(display));
     const list<value> aargs = mklist<value>(mklist<value>("response_type", "code"), mklist<value>("client_id", car(appkey)), mklist<value>("scope", cadr(scope)), adisplay, mklist<value>("redirect_uri", httpd::escape(redir)), mklist<value>("state", httpd::escape(state)));
     const string uri = httpd::unescape(cadr(auth)) + string("?") + http::queryString(aargs);
     debug(uri, "modoauth2::authorize::uri");
@@ -233,28 +233,28 @@ const failable<int> accessToken(const list<value>& args, request_rec* r, const l
 
     // Extract access_token URI, client ID and authorization code parameters
     const list<value> state = assoc<value>("state", args);
-    if (isNil(state) || isNil(cdr(state)))
+    if (isNull(state) || isNull(cdr(state)))
         return mkfailure<int>("Missing state parameter");
     const list<value>& stargs = httpd::queryArgs(httpd::unescape(cadr(state)));
     const list<value> ref = assoc<value>("openauth_referrer", stargs);
-    if (isNil(ref) || isNil(cdr(ref)))
+    if (isNull(ref) || isNull(cdr(ref)))
         return mkfailure<int>("Missing openauth_referrer parameter");
     const list<value> tok = assoc<value>("oauth2_access_token", stargs);
-    if (isNil(tok) || isNil(cdr(tok)))
+    if (isNull(tok) || isNull(cdr(tok)))
         return mkfailure<int>("Missing oauth2_access_token parameter");
     const list<value> cid = assoc<value>("oauth2_client_id", stargs);
-    if (isNil(cid) || isNil(cdr(cid)))
+    if (isNull(cid) || isNull(cdr(cid)))
         return mkfailure<int>("Missing oauth2_client_id parameter");
     const list<value> info = assoc<value>("oauth2_info", stargs);
-    if (isNil(info) || isNil(cdr(info)))
+    if (isNull(info) || isNull(cdr(info)))
         return mkfailure<int>("Missing oauth2_info parameter");
     const list<value> code = assoc<value>("code", args);
-    if (isNil(code) || isNil(cdr(code)))
+    if (isNull(code) || isNull(cdr(code)))
         return mkfailure<int>("Missing code parameter");
 
     // Lookup client app configuration
     const list<value> app = assoc<value>(cadr(cid), appkeys);
-    if (isNil(app) || isNil(cdr(app)))
+    if (isNull(app) || isNull(cdr(app)))
         return mkfailure<int>(string("client id not found: ") + (string)cadr(cid));
     list<value> appkey = cadr(app);
 
@@ -274,12 +274,12 @@ const failable<int> accessToken(const list<value>& args, request_rec* r, const l
         return mkfailure<int>(ftr);
     const value tr = content(ftr);
     debug(tr, "modoauth2::access_token::response");
-    if (!isList(tr) || isNil(tr))
+    if (!isList(tr) || isNull(tr))
         return mkfailure<int>("Empty access token");
     const list<value> tv = isString(car<value>(tr)) ?
         assoc<value>("access_token", httpd::queryArgs(join("", convertValues<string>(cadr<value>(tr))))) :
         assoc<value>("access_token", tr);
-    if (isNil(tv) || isNil(cdr(tv)))
+    if (isNull(tv) || isNull(cdr(tv)))
         return mkfailure<int>("Couldn't retrieve access_token");
     debug(tv, "modoauth2::access_token::token");
 
@@ -373,7 +373,7 @@ static int checkAuthn(request_rec *r) {
         hasContent(openauth::sessionID(r, "TuscanyOpenAuth")) ||
         hasContent(openauth::sessionID(r, "TuscanyOAuth1")))
         return DECLINED;
-    if ((substr(string(r->uri), 0, 8) == "/oauth1/") || !isNil(assoc<value>("openid_identifier", args)))
+    if ((substr(string(r->uri), 0, 8) == "/oauth1/") || !isNull(assoc<value>("openid_identifier", args)))
         return DECLINED;
 
     r->ap_auth_type = const_cast<char*>(atype);
@@ -390,9 +390,9 @@ int postConfigMerge(const ServerConf& mainsc, server_rec* const s) {
     debug(httpd::serverName(s), "modoauth2::postConfigMerge::serverName");
 
     // Merge configuration from main server
-    if (isNil((list<value>)sc.appkeys))
+    if (isNull((list<value>)sc.appkeys))
         sc.appkeys = mainsc.appkeys;
-    if (isNil((list<string>)sc.mcaddrs))
+    if (isNull((list<string>)sc.mcaddrs))
         sc.mcaddrs = mainsc.mcaddrs;
     sc.mc = mainsc.mc;
     sc.cs = mainsc.cs;
@@ -424,7 +424,7 @@ void childInit(apr_pool_t* const p, server_rec* const s) {
     ServerConf& sc = *psc;
 
     // Connect to Memcached
-    if (isNil((list<string>)sc.mcaddrs))
+    if (isNull((list<string>)sc.mcaddrs))
         sc.mc = *(new (gc_new<memcache::MemCached>()) memcache::MemCached("localhost", 11211));
     else
         sc.mc = *(new (gc_new<memcache::MemCached>()) memcache::MemCached(sc.mcaddrs));
diff --git a/sca-cpp/trunk/modules/opencl/driver.hpp b/sca-cpp/trunk/modules/opencl/driver.hpp
index c45bcf6ee4..f60e9c1dd3 100644
--- a/sca-cpp/trunk/modules/opencl/driver.hpp
+++ b/sca-cpp/trunk/modules/opencl/driver.hpp
@@ -38,7 +38,7 @@ namespace opencl {
 const value evalDriverLoop(const OpenCLProgram& clprog, istream& in, ostream& out, const OpenCLContext& cl) {
     scheme::promptForInput(scheme::evalInputPrompt, out);
     const value input = content(scheme::readValue(in));
-    if (isNil(input))
+    if (isNull(input))
         return input;
     const failable<value> output = evalKernel(createKernel(input, clprog), input, 1, value::String, 512, cl);
     scheme::announceOutput(scheme::evalOutputPrompt, out);
diff --git a/sca-cpp/trunk/modules/opencl/eval.hpp b/sca-cpp/trunk/modules/opencl/eval.hpp
index f842ba783d..e910d427bc 100644
--- a/sca-cpp/trunk/modules/opencl/eval.hpp
+++ b/sca-cpp/trunk/modules/opencl/eval.hpp
@@ -412,7 +412,7 @@ const failable<OpenCLBuffer> readOnlyBuffer(const size_t size, const void* const
  * Fill an array of write events for a given list of buffers.
  */
 const cl_uint writeBufferEvents(const list<OpenCLBuffer>& buf, cl_event* const evt) {
-    if (isNil(buf))
+    if (isNull(buf))
         return 0;
     const cl_event e = car(buf).evt;
     if (e == 0)
@@ -486,7 +486,7 @@ const failable<OpenCLBuffer> valueToKernelArg(const value& v, const cl_uint i, c
  * Convert a list of values to kernel args.
  */
 const failable<list<OpenCLBuffer>> valuesToKernelArgsListHelper(const list<value>& v, const cl_uint i, const OpenCLKernel& kernel, const OpenCLContext& cl, const cl_command_queue cq) {
-    if (isNil(v))
+    if (isNull(v))
         return list<OpenCLBuffer>();
     const failable<OpenCLBuffer> a = valueToKernelArg(car(v), i, kernel, cl, cq);
     if (!hasContent(a))
diff --git a/sca-cpp/trunk/modules/python/driver.hpp b/sca-cpp/trunk/modules/python/driver.hpp
index 41daed32c3..3b02302c65 100644
--- a/sca-cpp/trunk/modules/python/driver.hpp
+++ b/sca-cpp/trunk/modules/python/driver.hpp
@@ -38,7 +38,7 @@ namespace python {
 const value evalDriverLoop(PyObject* const script, istream& in, ostream& out, PythonRuntime& py) {
     scheme::promptForInput(scheme::evalInputPrompt, out);
     const value input = content(scheme::readValue(in));
-    if (isNil(input))
+    if (isNull(input))
         return input;
     const failable<value> output = evalScript(input, script, py);
     scheme::announceOutput(scheme::evalOutputPrompt, out);
diff --git a/sca-cpp/trunk/modules/python/eval.hpp b/sca-cpp/trunk/modules/python/eval.hpp
index 3f9c6c20a2..3728cdb7bb 100644
--- a/sca-cpp/trunk/modules/python/eval.hpp
+++ b/sca-cpp/trunk/modules/python/eval.hpp
@@ -483,7 +483,7 @@ PyObject* const mkPyLambda(const lvvlambda& l, PythonRuntime* const py) {
  * Convert a list of values to a python list.
  */
 PyObject* const valuesToPyListHelper(PyObject* const l, const list<value>& v, PythonRuntime* const py) {
-    if (isNil(v))
+    if (isNull(v))
         return l;
     PyObject* const pyv = valueToPyObject(car(v), py);
     PyList_Append(l, pyv);
diff --git a/sca-cpp/trunk/modules/python/python-test.cpp b/sca-cpp/trunk/modules/python/python-test.cpp
index 44a72f8f88..65b18c9b1b 100644
--- a/sca-cpp/trunk/modules/python/python-test.cpp
+++ b/sca-cpp/trunk/modules/python/python-test.cpp
@@ -197,7 +197,7 @@ const list<future<bool> > submitEvals(worker& w, const int max, const int i, PyO
 }
 
 const bool checkEvalResults(const list<future<bool> > r) {
-    if (isNil(r))
+    if (isNull(r))
         return true;
     assert(car(r) == true);
     return checkEvalResults(cdr(r));
diff --git a/sca-cpp/trunk/modules/rss/rss.hpp b/sca-cpp/trunk/modules/rss/rss.hpp
index 348d50e8f3..e8edc0dcb1 100644
--- a/sca-cpp/trunk/modules/rss/rss.hpp
+++ b/sca-cpp/trunk/modules/rss/rss.hpp
@@ -46,14 +46,14 @@ const value entry("entry");
  */
 const list<value> entryElementValues(const list<value>& e) {
     const list<value> lt = elementChildren("title", e);
-    const value t = isNil(lt)? value(emptyString) : elementValue(car(lt));
+    const value t = isNull(lt)? value(emptyString) : elementValue(car(lt));
     const list<value> li = elementChildren("link", e);
-    const value i = isNil(li)? value(emptyString) : elementValue(car(li));
+    const value i = isNull(li)? value(emptyString) : elementValue(car(li));
     const list<value> ld = elementChildren("description", e);
     return append<value>(nilListValue + element + entry 
                 + value(nilListValue + element + value("title") + t)
                 + value(nilListValue + element + value("id") + i),
-                isNil(ld)? nilListValue : isAttribute(elementValue(car(ld)))? nilListValue :
+                isNull(ld)? nilListValue : isAttribute(elementValue(car(ld)))? nilListValue :
                     mklist<value>(value(nilListValue + element + value("content") + elementValue(car(ld)))));
 }
 
@@ -61,7 +61,7 @@ const list<value> entryElementValues(const list<value>& e) {
  * Convert a list of elements to a list of element values representing ATOM entries.
  */
 const list<value> entriesElementValues(const list<value>& e) {
-    if (isNil(e))
+    if (isNull(e))
         return e;
     return cons<value>(entryElementValues(car(e)), entriesElementValues(cdr(e)));
 }
@@ -80,7 +80,7 @@ const bool isRSSFeed(const list<string>& ls) {
  */
 const failable<list<value> > readRSSEntry(const list<string>& ilist) {
     const list<value> e = content(xml::readElements(ilist));
-    if (isNil(e))
+    if (isNull(e))
         return mkfailure<list<value> >("Empty entry");
     return mklist<value>(entryElementValues(car(e)));
 }
@@ -90,7 +90,7 @@ const failable<list<value> > readRSSEntry(const list<string>& ilist) {
  */
 const failable<list<value> > readRSSFeed(const list<string>& ilist) {
     const list<value> f = content(xml::readElements(ilist));
-    if (isNil(f))
+    if (isNull(f))
         return mkfailure<list<value> >("Empty feed");
     const list<value> c = elementChildren("channel", car(f));
     const list<value> t = elementChildren("title", car(c));
@@ -109,12 +109,12 @@ const list<value> entryElement(const list<value>& l) {
     const value title = elementValue(elementChild("title", l));
     const value id = elementValue(elementChild("id", l));
     const value content = elementChild("content", l);
-    const bool text = isNil(content)? false : elementHasValue(content);
+    const bool text = isNull(content)? false : elementHasValue(content);
     return append<value>(nilListValue
         + element + "item"
         + (nilListValue + element + "title" + title)
         + (nilListValue + element + "link" + id),
-        isNil(content)?
+        isNull(content)?
             nilListValue :
             mklist<value>(append<value>(nilListValue + element + "description",
                 text? mklist<value>(elementValue(content)) : elementChildren(content))));
@@ -124,7 +124,7 @@ const list<value> entryElement(const list<value>& l) {
  * Convert a list of values representing RSS entries to a list of elements.
  */
 const list<value> entriesElements(const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons<value>(entryElement(car(l)), entriesElements(cdr(l)));
 }
@@ -134,7 +134,7 @@ const list<value> entriesElements(const list<value>& l) {
  * The first two values in the list are the entry id and title.
  */
 template<typename R> const failable<R> writeRSSEntry(const lambda<const R(const string&, const R)>& reduce, const R& initial, const list<value>& ll) {
-    const list<value> l = isNil(ll)? ll : (list<value>)car(ll);
+    const list<value> l = isNull(ll)? ll : (list<value>)car(ll);
     return xml::writeElements<R>(reduce, initial, mklist<value>(entryElement(l)));
 }
 
@@ -150,11 +150,11 @@ const failable<list<string> > writeRSSEntry(const list<value>& l) {
  * The first two values in the list are the feed id and title.
  */
 template<typename R> const failable<R> writeRSSFeed(const lambda<const R(const string&, const R)>& reduce, const R& initial, const list<value>& ll) {
-    const list<value> l = isNil(ll)? ll : (list<value>)car(ll);
+    const list<value> l = isNull(ll)? ll : (list<value>)car(ll);
     const list<value> lt = elementChildren("title", l);
-    const value t = isNil(lt)? value(emptyString) : elementValue(car(lt));
+    const value t = isNull(lt)? value(emptyString) : elementValue(car(lt));
     const list<value> li = elementChildren("id", l);
-    const value i = isNil(li)? value(emptyString) : elementValue(car(li));
+    const value i = isNull(li)? value(emptyString) : elementValue(car(li));
     const list<value> c = nilListValue
         + (nilListValue + element + "title" + t)
         + (nilListValue + element + "link" + i)
@@ -162,7 +162,7 @@ template<typename R> const failable<R> writeRSSFeed(const lambda<const R(const s
 
     // Write RSS entries
     const list<value> le = elementChildren(entry, l);
-    if (isNil(le)) {
+    if (isNull(le)) {
         const list<value> fe = nilListValue
             + element + "rss" + (nilListValue + attribute + "version" + "2.0")
             + append(nilListValue + element + "channel", c);
@@ -170,7 +170,7 @@ template<typename R> const failable<R> writeRSSFeed(const lambda<const R(const s
     }
 
     // Write a single RSS entry element with a list of values
-    if (!isNil(le) && !isNil(car(le)) && isList(car<value>(caddr<value>(car(le))))) {
+    if (!isNull(le) && !isNull(car(le)) && isList(car<value>(caddr<value>(car(le))))) {
         const list<value> ce = append(c, entriesElements(caddr<value>(car(le))));
         const list<value> fe = nilListValue
             + element + "rss" + (nilListValue + attribute + "version" + "2.0")
diff --git a/sca-cpp/trunk/modules/scdl/scdl.hpp b/sca-cpp/trunk/modules/scdl/scdl.hpp
index 35a717d478..98afbe604c 100644
--- a/sca-cpp/trunk/modules/scdl/scdl.hpp
+++ b/sca-cpp/trunk/modules/scdl/scdl.hpp
@@ -40,7 +40,7 @@ namespace scdl {
  */
 const list<value> components(const value& l) {
     const list<value> cs = elementChildren("composite", l);
-    if (isNil(cs))
+    if (isNull(cs))
         return cs;
     return elementChildren("component", car(cs));
 }
@@ -50,7 +50,7 @@ const list<value> components(const value& l) {
  */
 const list<value> promotions(const value& l) {
     const list<value> cs = elementChildren("composite", l);
-    if (isNil(cs))
+    if (isNull(cs))
         return cs;
     return elementChildren("service", car(cs));
 }
@@ -73,7 +73,7 @@ const value name(const value& l) {
  * Convert a list of elements to a name -> element assoc list.
  */
 const list<value> nameToElementAssoc(const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     const value e(car(l));
     return cons<value>(mklist<value>(name(e), e), nameToElementAssoc(cdr(l)));
@@ -87,7 +87,7 @@ const value named(const value& n, const value& l) {
         return name(v) == n;
     };
     const list<value> c = filter<value>(filterName, l);
-    if (isNil(c))
+    if (isNull(c))
         return nilValue;
     return car(c);
 }
@@ -100,7 +100,7 @@ const value implementation(const value& l) {
         return isElement(v) && contains(string(cadr<value>(v)), "implementation.");
     };
     const list<value> n = filter<value>(filterImplementation, l);
-    if (isNil(n))
+    if (isNull(n))
         return nilValue;
     return car(n);
 }
@@ -148,17 +148,17 @@ const list<value> bindings(const value& l) {
  * Returns the target of a reference.
  */
 const value bindingsTarget(const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return nilValue;
     const value u = uri(car(l));
-    if (!isNil(u))
+    if (!isNull(u))
         return u;
     return bindingsTarget(cdr(l));
 }
 
 const value target(const value& l) {
     const value target = attributeValue("target", l);
-    if (!isNil(target))
+    if (!isNull(target))
         return target;
     return bindingsTarget(bindings(l));
 }
@@ -167,7 +167,7 @@ const value target(const value& l) {
  * Convert a list of references to a reference name -> target assoc list.
  */
 const list<value> referenceToTargetAssoc(const list<value>& r) {
-    if (isNil(r))
+    if (isNull(r))
         return r;
     const value ref(car(r));
     return cons<value>(mklist<value>(scdl::name(ref), scdl::target(ref)), referenceToTargetAssoc(cdr(r)));
diff --git a/sca-cpp/trunk/modules/scheme/driver.hpp b/sca-cpp/trunk/modules/scheme/driver.hpp
index c94af7bbf7..015348c9e1 100644
--- a/sca-cpp/trunk/modules/scheme/driver.hpp
+++ b/sca-cpp/trunk/modules/scheme/driver.hpp
@@ -56,7 +56,7 @@ const bool userPrint(const value val, ostream& out) {
 const value evalDriverLoop(istream& in, ostream& out, Env& env) {
     promptForInput(evalInputPrompt, out);
     const value input = content(readValue(in));
-    if (isNil(input))
+    if (isNull(input))
         return input;
     const value output = evalExpr(input, env);
     announceOutput(evalOutputPrompt, out);
diff --git a/sca-cpp/trunk/modules/scheme/environment.hpp b/sca-cpp/trunk/modules/scheme/environment.hpp
index 1a295c74f4..ee82bc0401 100644
--- a/sca-cpp/trunk/modules/scheme/environment.hpp
+++ b/sca-cpp/trunk/modules/scheme/environment.hpp
@@ -81,16 +81,16 @@ const bool isDotVariable(const value& var) {
 }
 
 const Frame makeBinding(const Frame& frameSoFar, const list<value>& variables, const list<value> values) {
-    if (isNil(variables)) {
-        if (!isNil(values))
+    if (isNull(variables)) {
+        if (!isNull(values))
             logStream() << "Too many arguments supplied " << values << endl;
         return frameSoFar;
     }
     if (isDotVariable(car(variables)))
         return makeBinding(frameSoFar, cdr(variables), mklist<value>(values));
 
-    if (isNil(values)) {
-        if (!isNil(variables))
+    if (isNull(values)) {
+        if (!isNull(variables))
             logStream() << "Too few arguments supplied " << variables << endl;
         return frameSoFar;
     }
@@ -118,7 +118,7 @@ const value definitionVariable(const value& exp) {
 const value definitionValue(const value& exp) {
     const list<value> exps(exp);
     if(isSymbol(car(cdr(exps)))) {
-        if (isNil(cdr(cdr(exps))))
+        if (isNull(cdr(cdr(exps))))
             return nilValue;
         return car(cdr(cdr(exps)));
     }
@@ -158,7 +158,7 @@ const Env setupEnvironment() {
 const value lookupEnvLoop(const value& var, const Env& env);
 
 const value lookupEnvScan(const value& var, const list<value>& vars, const list<value>& vals, const Env& env) {
-    if(isNil(vars))
+    if(isNull(vars))
         return lookupEnvLoop(var, enclosingEnvironment(env));
     if(var == car(vars))
         return car(vals);
diff --git a/sca-cpp/trunk/modules/scheme/eval.hpp b/sca-cpp/trunk/modules/scheme/eval.hpp
index 5074471931..17150a7b48 100644
--- a/sca-cpp/trunk/modules/scheme/eval.hpp
+++ b/sca-cpp/trunk/modules/scheme/eval.hpp
@@ -87,7 +87,7 @@ const list<value> operands(const value& exp) {
 }
 
 const list<value> listOfValues(const list<value> exps, Env& env) {
-    if(isNil(exps))
+    if(isNull(exps))
         return list<value> ();
     return cons(evalExpr(car(exps), env), listOfValues(cdr(exps), env));
 }
@@ -117,7 +117,7 @@ const Env procedureEnvironment(const value& exp) {
 }
 
 const bool isLastExp(const list<value>& seq) {
-    return isNil(cdr(seq));
+    return isNull(cdr(seq));
 }
 
 const value firstExp(const list<value>& seq) {
@@ -151,7 +151,7 @@ const value applyProcedure(const value& procedure, list<value>& arguments) {
 }
 
 const value sequenceToExp(const list<value> exps) {
-    if(isNil(exps))
+    if(isNull(exps))
         return exps;
     if(isLastExp(exps))
         return firstExp(exps);
@@ -179,7 +179,7 @@ const value ifConsequent(const value& exp) {
 }
 
 const value ifAlternative(const value& exp) {
-    if(!isNil(cdr(cdr(cdr((list<value> )exp)))))
+    if(!isNull(cdr(cdr(cdr((list<value> )exp)))))
         return car(cdr(cdr(cdr((list<value> )exp))));
     return false;
 }
@@ -201,12 +201,12 @@ const value makeIf(value predicate, value consequent, value alternative) {
 }
 
 const value expandClauses(const list<value>& clauses) {
-    if(isNil(clauses))
+    if(isNull(clauses))
         return false;
     const value first = car(clauses);
     const list<value> rest = cdr(clauses);
     if(isCondElseClause(first)) {
-        if(isNil(rest))
+        if(isNull(rest))
             return sequenceToExp(condActions(first));
         logStream() << "else clause isn't last " << clauses << endl;
         return nilValue;
@@ -259,7 +259,7 @@ const value evalExpr(const value& exp, Env& env) {
 }
 
 const list<value> quotedParameters(const list<value>& p) {
-    if (isNil(p))
+    if (isNull(p))
         return p;
     return cons<value>(mklist<value>(quoteSymbol, car(p)), quotedParameters(cdr(p)));
 }
@@ -268,7 +268,7 @@ const list<value> quotedParameters(const list<value>& p) {
  * Evaluate an expression against a script provided as a list of values.
  */
 const value evalScriptLoop(const value& expr, const list<value>& script, scheme::Env& env) {
-    if (isNil(script))
+    if (isNull(script))
         return scheme::evalExpr(expr, env);
     scheme::evalExpr(car(script), env);
     return evalScriptLoop(expr, cdr(script), env);
diff --git a/sca-cpp/trunk/modules/scheme/io.hpp b/sca-cpp/trunk/modules/scheme/io.hpp
index 02f6923c86..c7177b54ae 100644
--- a/sca-cpp/trunk/modules/scheme/io.hpp
+++ b/sca-cpp/trunk/modules/scheme/io.hpp
@@ -231,7 +231,7 @@ inline const failable<list<string> > writeValue(const value& val) {
 
 inline const value readScript(istream& in) {
     const value val = content(readValue(in));
-    if (isNil(val))
+    if (isNull(val))
         return nilListValue;
     return cons(val, (list<value>)readScript(in));
 }
diff --git a/sca-cpp/trunk/modules/scheme/primitive.hpp b/sca-cpp/trunk/modules/scheme/primitive.hpp
index 4815e9a497..da0056d6da 100644
--- a/sca-cpp/trunk/modules/scheme/primitive.hpp
+++ b/sca-cpp/trunk/modules/scheme/primitive.hpp
@@ -118,10 +118,10 @@ inline const value treeSelectAssocProc(const list<value>& args) {
 
 inline const value nullProc(const list<value>& args) {
     const value v(car(args));
-    if (isNil(v))
+    if (isNull(v))
         return true;
     if (isList(v))
-        return isNil(list<value>(v));
+        return isNull(list<value>(v));
     return false;
 }
 
@@ -138,13 +138,13 @@ inline const value lesserProc(const list<value>& args) {
 }
 
 inline const value addProc(const list<value>& args) {
-    if (isNil(cdr(args)))
+    if (isNull(cdr(args)))
         return (double)car(args);
     return (double)car(args) + (double)cadr(args);
 }
 
 inline const value subProc(const list<value>& args) {
-    if (isNil(cdr(args)))
+    if (isNull(cdr(args)))
         return (double)0 - (double)car(args);
     return (double)car(args) - (double)cadr(args);
 }
@@ -162,7 +162,7 @@ inline const value sqrtProc(const list<value>& args) {
 }
 
 inline const value displayProc(const list<value>& args) {
-    if (isNil(args)) {
+    if (isNull(args)) {
         displayStream() << endl;
         return true;
     }
@@ -171,7 +171,7 @@ inline const value displayProc(const list<value>& args) {
 }
 
 inline const value logProc(const list<value>& args) {
-    if (isNil(args)) {
+    if (isNull(args)) {
         logStream() << endl;
         return true;
     }
@@ -225,7 +225,7 @@ inline const bool isPrimitiveProcedure(const value& proc) {
 }
 
 inline const bool isSelfEvaluating(const value& exp) {
-    if(isNil(exp))
+    if(isNull(exp))
         return true;
     if(isNumber(exp))
         return true;
diff --git a/sca-cpp/trunk/modules/server/client-test.hpp b/sca-cpp/trunk/modules/server/client-test.hpp
index 29da9e4798..562fe9c68e 100644
--- a/sca-cpp/trunk/modules/server/client-test.hpp
+++ b/sca-cpp/trunk/modules/server/client-test.hpp
@@ -190,7 +190,7 @@ const list<future<bool> > startPost(worker& w, const int threads, const blambda&
 }
 
 const bool checkPost(const list<future<bool> >& r) {
-    if (isNil(r))
+    if (isNull(r))
         return true;
     assert(car(r) == true);
     return checkPost(cdr(r));
@@ -244,7 +244,7 @@ const list<pid_t> startPost(const int procs, const blambda& l) {
 }
 
 const bool checkPost(const list<pid_t>& r) {
-    if (isNil(r))
+    if (isNull(r))
         return true;
     int status;
     waitpid(car(r), &status, 0);
diff --git a/sca-cpp/trunk/modules/server/mod-cpp.hpp b/sca-cpp/trunk/modules/server/mod-cpp.hpp
index 1321466383..54742306b0 100644
--- a/sca-cpp/trunk/modules/server/mod-cpp.hpp
+++ b/sca-cpp/trunk/modules/server/mod-cpp.hpp
@@ -46,7 +46,7 @@ namespace modcpp {
  * Apply a C++ component implementation function.
  */
 const list<value> failableResult(const value& func, const list<value>& v) {
-    if (isNil(cdr(v)))
+    if (isNull(cdr(v)))
         return v;
 
     // Report a failure with an empty reason as 'function not supported'
@@ -69,7 +69,7 @@ const failable<lvvlambda > evalImplementation(const string& path, const value& i
     // Configure the implementation's lambda function
     const value ipath(attributeValue("path", impl));
     const value iname(attributeValue("library", impl));
-    const string fpath(isNil(ipath)? path + (string)iname : path + (string)ipath + "/" + (string)iname);
+    const string fpath(isNull(ipath)? path + (string)iname : path + (string)ipath + "/" + (string)iname);
     const lib ilib(*(new (gc_new<lib>()) lib(fpath + dynlibExt)));
     const failable<lvvlambda > fappl(dynlambda<const value(const list<value>&)>("apply", ilib));
     if (!hasContent(fappl))
diff --git a/sca-cpp/trunk/modules/server/mod-eval.hpp b/sca-cpp/trunk/modules/server/mod-eval.hpp
index 5a8a15bf43..204459e127 100644
--- a/sca-cpp/trunk/modules/server/mod-eval.hpp
+++ b/sca-cpp/trunk/modules/server/mod-eval.hpp
@@ -161,9 +161,9 @@ static APR_OPTIONAL_FN_TYPE(ap_authn_cache_store) *authnCacheStore = NULL;
  * failable monad.
  */
 const failable<value> failableResult(const list<value>& v) {
-    if (isNil(cdr(v)))
+    if (isNull(cdr(v)))
         return car(v);
-    return mkfailure<value>(string(cadr(v)), isNil(cddr(v))? -1 : (int)caddr(v), false);
+    return mkfailure<value>(string(cadr(v)), isNull(cddr(v))? -1 : (int)caddr(v), false);
 }
 
 /**
@@ -207,7 +207,7 @@ public:
 
         // Lookup the component implementation
         const list<value> impl(rbtreeAssoc<value>(cname, (list<value>)impls));
-        if (isNil(impl))
+        if (isNull(impl))
             return mkfailure<value>(string("Couldn't find component implementation: ") + (string)cname);
 
         // Call its lambda function
@@ -225,7 +225,7 @@ public:
         debug(params, "modeval::implProxy::input");
 
         // If the reference was 'wiredByImpl' use the first param as target
-        if (isNil(name)) {
+        if (isNull(name)) {
             const value uri = cadr(params);
             const list<value> aparams = cons<value>(car(params), cddr(params));
             debug(uri, "modeval::implProxy::wiredByImpl::uri");
@@ -313,7 +313,7 @@ const value mkrefProxy(const value& ref, const gc_mutable_ref<list<value> >& imp
     // Use an HTTP proxy or an internal proxy to the component implementation
     if (wbyimpl)
         return mkimplProxy(nilValue, impls, sslc, timeout);
-    if (isNil(target))
+    if (isNull(target))
         return mkunwiredProxy(scdl::name(ref));
     if (http::isAbsolute(target))
         return mkhttpProxy(target, timeout);
@@ -321,7 +321,7 @@ const value mkrefProxy(const value& ref, const gc_mutable_ref<list<value> >& imp
 }
 
 const list<value> refProxies(const list<value>& refs, const gc_mutable_ref<list<value> >& impls, const SSLConf& sslc, const int timeout) {
-    if (isNil(refs))
+    if (isNull(refs))
         return refs;
     return cons(mkrefProxy(car(refs), impls, sslc, timeout), refProxies(cdr(refs), impls, sslc, timeout));
 }
@@ -352,7 +352,7 @@ const lvvlambda mkappPropProxy(const value& v) {
         if (currentRequest == NULL)
             return v;
         const RequestConf& reqc = httpd::requestConf<RequestConf>(currentRequest, &mod_tuscany_eval);
-        const value a = isNil((const list<value>)reqc.vpath)? v : car((const list<value>)reqc.vpath);
+        const value a = isNull((const list<value>)reqc.vpath)? v : car((const list<value>)reqc.vpath);
         debug(a, "modeval::appPropProxy::value");
         return a;
     };
@@ -463,7 +463,7 @@ const value mkpropProxy(const value& prop) {
 }
 
 const list<value> propProxies(const list<value>& props) {
-    if (isNil(props))
+    if (isNull(props))
         return props;
     return cons(mkpropProxy(car(props)), propProxies(cdr(props)));
 }
@@ -505,7 +505,7 @@ const value evalComponent(const string& contribPath, const value& comp, const gc
  * Return a list of component-name + configured-implementation pairs.
  */
 const list<value> componentToImplementationAssoc(const list<value>& c, const string& contribPath, const gc_mutable_ref<list<value> >& impls, const lvvlambda& lifecycle, const SSLConf& sslc, const int timeout) {
-    if (isNil(c))
+    if (isNull(c))
         return c;
     return cons<value>(mklist<value>(scdl::name(car(c)),
                 evalComponent(contribPath, car(c), impls, lifecycle, sslc, timeout)),
@@ -531,11 +531,11 @@ const failable<list<value> > getComponents(const lvvlambda& contributor, const s
         return mkfailure<list<value> >(val);
     debug(content(val), "modeval::getComponents::val");
     const list<value> valc = assoc<value>(value("content"), cdr<value>(car<value>(content(val))));
-    if (isNil(valc))
+    if (isNull(valc))
         return mkfailure<list<value> >(string("Could not get composite: ") + name);
     const list<value> comp = assoc<value>(value("composite"), cdr<value>(valc));
     debug(comp, "modeval::getComponents::comp");
-    if (isNil(comp))
+    if (isNull(comp))
         return mkfailure<list<value> >(string("Could not get composite: ") + name);
     const failable<list<string> > x = xml::writeElements(car<value>(valuesToElements(mklist<value>(mklist<value>(comp)))));
     if (!hasContent(x))
@@ -548,7 +548,7 @@ const failable<list<value> > getComponents(const lvvlambda& contributor, const s
  * Return the functions returned by the component implementations.
  */
 const failable<list<value> > applyLifecycleExpr(const list<value>& impls, const list<value>& expr) {
-    if (isNil(impls))
+    if (isNull(impls))
         return nilListValue;
 
     // Evaluate lifecycle expression against a component implementation lambda
@@ -559,7 +559,7 @@ const failable<list<value> > applyLifecycleExpr(const list<value>& impls, const
     const lvvlambda rl = content(r);
 
     // Use the returned lambda function, if any, from now on
-    const lvvlambda al = isNil(rl)? l : rl;
+    const lvvlambda al = isNull(rl)? l : rl;
 
     // Continue with the rest of the list
     const failable<list<value> > nr = applyLifecycleExpr(cdr(impls), expr);
@@ -577,7 +577,7 @@ const list<value> componentReferenceToTargetTree(const value& c) {
 }
 
 const list<value> componentReferenceToTargetAssoc(const list<value>& c) {
-    if (isNil(c))
+    if (isNull(c))
         return c;
     return cons<value>(componentReferenceToTargetTree(car(c)), componentReferenceToTargetAssoc(cdr(c)));
 }
@@ -591,26 +591,26 @@ const list<value> defaultBindingURI(const string& cn, const string& sn) {
 }
 
 const list<value> bindingToComponentAssoc(const string& cn, const string& sn, const list<value>& b) {
-    if (isNil(b))
+    if (isNull(b))
         return b;
     const value uri(scdl::uri(car(b)));
-    if (isNil(uri))
+    if (isNull(uri))
         return cons<value>(mklist<value>(defaultBindingURI(cn, sn), cn), bindingToComponentAssoc(cn, sn, cdr(b)));
     return cons<value>(mklist<value>(pathValues(c_str(string(uri))), cn), bindingToComponentAssoc(cn, sn, cdr(b)));
 }
 
 const list<value> serviceToComponentAssoc(const string& cn, const list<value>& s) {
-    if (isNil(s))
+    if (isNull(s))
         return s;
     const string sn(scdl::name(car(s)));
     const list<value> btoc(bindingToComponentAssoc(cn, sn, scdl::bindings(car(s))));
-    if (isNil(btoc))
+    if (isNull(btoc))
         return cons<value>(mklist<value>(defaultBindingURI(cn, sn), cn), serviceToComponentAssoc(cn, cdr(s)));
     return append<value>(btoc, serviceToComponentAssoc(cn, cdr(s)));
 }
 
 const list<value> uriToComponentAssoc(const list<value>& c) {
-    if (isNil(c))
+    if (isNull(c))
         return c;
     return append<value>(serviceToComponentAssoc(scdl::name(car(c)), scdl::services(car(c))), uriToComponentAssoc(cdr(c)));
 }
@@ -625,7 +625,7 @@ const failable<Composite> confComponents(const string& contribPath, const string
     debug(vhost, "modeval::confComponents::vhost");
     debug(impls, "modeval::confComponents::impls");
 
-    const failable<list<value> > fcomps = isNil(contributor)?
+    const failable<list<value> > fcomps = isNull(contributor)?
         readComponents(scdl::resourcePath(length(vhost) != 0? contribPath + vhost + "/" : contribPath, composName)) :
         getComponents(contributor, vhost);
     if (!hasContent(fcomps))
@@ -641,7 +641,7 @@ const failable<Composite> confComponents(const string& contribPath, const string
     debug(flatten(svcs), "modeval::confComponents::svcs");
 
     const list<value> cimpls = mkbrbtree(sort(componentToImplementationAssoc(comps,
-                    isNil(contributor)? length(vhost) != 0? contribPath + vhost + "/" : contribPath : contribPath,
+                    isNull(contributor)? length(vhost) != 0? contribPath + vhost + "/" : contribPath : contribPath,
                     impls, lifecycle, sslc, timeout)));
     debug(flatten(cimpls), "modeval::confComponents::impls");
 
@@ -701,7 +701,7 @@ const failable<int> get(const list<value>& rpath, request_rec* const r, const lv
     const list<value> ma = assoc(value("method"), args);
 
     // Evaluate a JSON-RPC request and return a JSON result
-    if (!isNil(ia) && !isNil(ma)) {
+    if (!isNull(ia) && !isNull(ma)) {
 
         // Extract the request id, method and params
         const value id = cadr(ia);
@@ -725,13 +725,13 @@ const failable<int> get(const list<value>& rpath, request_rec* const r, const lv
     debug(c, "modeval::get::content");
 
     // Return a nil value as a not found status
-    if (!isList(c) && isNil(c))
+    if (!isList(c) && isNull(c))
         return HTTP_NOT_FOUND;
 
     // Write in the format requested by the client, if any
     const list<value> fmt = assoc<value>("format", args);
-    const value mtype = !isNil(fmt)? cadr(fmt) : acceptMediaType(r);
-    if (!isNil(mtype)) {
+    const value mtype = !isNull(fmt)? cadr(fmt) : acceptMediaType(r);
+    if (!isNull(mtype)) {
         if (mtype == "scheme")
             return httpd::writeResult(scheme::writeValue(c), "text/x-scheme; charset=utf-8", r);
         if (mtype == "json")
@@ -747,26 +747,26 @@ const failable<int> get(const list<value>& rpath, request_rec* const r, const lv
     }
 
     // Write an empty list as a JSON value
-    if (isNil((list<value>)c)) {
+    if (isNull((list<value>)c)) {
         debug(nilListValue, "modeval::get::empty");
         return httpd::writeResult(json::writeValue(c), "application/json; charset=utf-8", r);
     }
 
     // Write content-type / content-list pair
-    if (isString(car<value>(c)) && !isNil(cdr<value>(c)) && isList(cadr<value>(c)))
+    if (isString(car<value>(c)) && !isNull(cdr<value>(c)) && isList(cadr<value>(c)))
         return httpd::writeResult(convertValues<string>(cadr<value>(c)), car<value>(c), r);
 
     // Write an assoc value as a JSON value
-    if (isSymbol(car<value>(c)) && !isNil(cdr<value>(c))) {
+    if (isSymbol(car<value>(c)) && !isNull(cdr<value>(c))) {
         debug(c, "modeval::get::assoc");
         return httpd::writeResult(json::writeValue(c), "application/json; charset=utf-8", r);
     }
 
     // Write an ATOM feed or entry
     const list<value> e = valuesToElements(c);
-    if (isList(car<value>(e)) && !isNil(car<value>(e))) {
+    if (isList(car<value>(e)) && !isNull(car<value>(e))) {
         const list<value> el = car<value>(e);
-        if (isSymbol(car<value>(el)) && car<value>(el) == element && !isNil(cdr<value>(el)) && isSymbol(cadr<value>(el)) && elementHasChildren(el) && !elementHasValue(el)) {
+        if (isSymbol(car<value>(el)) && car<value>(el) == element && !isNull(cdr<value>(el)) && isSymbol(cadr<value>(el)) && elementHasChildren(el) && !elementHasValue(el)) {
             if (cadr<value>(el) == atom::feed)
                 return httpd::writeResult(atom::writeATOMFeed(e), "application/atom+xml; charset=utf-8", r);
             if (cadr<value>(el) == atom::entry)
@@ -829,7 +829,7 @@ const failable<int> post(const list<value>& rpath, request_rec* const r, const l
 
         // Report HTTP status code
         const value rval = content(val);
-        if (isNil(rval) || rval == falseValue)
+        if (isNull(rval) || rval == falseValue)
             return HTTP_NOT_FOUND;
         if (isNumber(rval))
             return (int)rval;
@@ -870,7 +870,7 @@ const failable<int> put(const list<value>& rpath, request_rec* const r, const lv
 
     // Report HTTP status
     const value rval = content(val);
-    if (isNil(rval) || rval == falseValue)
+    if (isNull(rval) || rval == falseValue)
         return HTTP_NOT_FOUND;
     if (isNumber(rval))
         return (int)rval;
@@ -898,7 +898,7 @@ const failable<int> patch(const list<value>& rpath, request_rec* const r, const
 
     // Report HTTP status
     const value rval = content(val);
-    if (isNil(rval) || rval == falseValue)
+    if (isNull(rval) || rval == falseValue)
         return HTTP_NOT_FOUND;
     if (isNumber(rval))
         return (int)rval;
@@ -918,7 +918,7 @@ const failable<int> del(const list<value>& rpath, request_rec* const r, const lv
 
     // Report HTTP status
     const value rval = content(val);
-    if (isNil(rval) || rval == falseValue)
+    if (isNull(rval) || rval == falseValue)
         return HTTP_NOT_FOUND;
     if (isNumber(rval))
         return (int)rval;
@@ -954,10 +954,10 @@ int translateComponent(request_rec* const r, const list<value>& rpath, const lis
     debug(flatten(impls), "modeval::translateComponent::impls");
 
     // Find the requested component
-    if (isNil(cdr(rpath)))
+    if (isNull(cdr(rpath)))
         return HTTP_NOT_FOUND;
     const list<value> impl(rbtreeAssoc(cadr(rpath), impls));
-    if (isNil(impl))
+    if (isNull(impl))
         return HTTP_NOT_FOUND;
     debug(impl, "modeval::translateComponent::impl");
 
@@ -973,16 +973,16 @@ int translateReference(request_rec* const r, const list<value>& rpath, const lis
     debug(flatten(refs), "modeval::translateReference::refs");
 
     // Find the requested component
-    if (isNil(cdr(rpath)))
+    if (isNull(cdr(rpath)))
         return HTTP_NOT_FOUND;
     const list<value> comp(rbtreeAssoc(cadr(rpath), refs));
-    if (isNil(comp))
+    if (isNull(comp))
         return HTTP_NOT_FOUND;
     debug(comp, "modeval::translateReference::comp");
 
     // Find the requested reference and target configuration
     const list<value> ref(rbtreeAssoc<value>(caddr(rpath), cadr(comp)));
-    if (isNil(ref))
+    if (isNull(ref))
         return HTTP_NOT_FOUND;
     debug(ref, "modeval::translateReference::ref");
 
@@ -1014,9 +1014,9 @@ int translateReference(request_rec* const r, const list<value>& rpath, const lis
  * Find a leaf matching a request path in a tree of URI paths.
  */
 const int matchPath(const list<value>& k, const list<value>& p) {
-    if (isNil(p))
+    if (isNull(p))
         return true;
-    if (isNil(k))
+    if (isNull(k))
         return false;
     if (car(k) != car(p))
         return false;
@@ -1024,7 +1024,7 @@ const int matchPath(const list<value>& k, const list<value>& p) {
 }
 
 const list<value> assocPath(const value& k, const list<value>& tree) {
-    if (isNil(tree))
+    if (isNull(tree))
         return tree;
     if (matchPath(k, car<value>(car(tree))))
         return car(tree);
@@ -1041,10 +1041,10 @@ int translateService(request_rec* const r, const list<value>& rpath, const list<
     debug(flatten(svcs), "modeval::translateService::svcs");
 
     // Find the requested component
-    if (isNil(rpath))
+    if (isNull(rpath))
         return HTTP_NOT_FOUND;
     const list<value> svc(assocPath(rpath, svcs));
-    if (isNil(svc))
+    if (isNull(svc))
         return DECLINED;
     debug(svc, "modeval::translateService::svc");
 
@@ -1061,7 +1061,7 @@ int translateService(request_rec* const r, const list<value>& rpath, const list<
 const int translateRequest(request_rec* const r, const list<value>& rpath, const list<value>& vpath, const list<value>& refs, const list<value>& svcs, const list<value>& impls) {
     debug(vpath, "modeval::translateRequest::vpath");
     debug(rpath, "modeval::translateRequest::rpath");
-    const string prefix = isNil(rpath)? emptyStringValue : car(rpath);
+    const string prefix = isNull(rpath)? emptyStringValue : car(rpath);
 
     // Translate a component request
     if ((prefix == string("components") || prefix == string("c")) && translateComponent(r, rpath, vpath, impls) == OK)
@@ -1076,7 +1076,7 @@ const int translateRequest(request_rec* const r, const list<value>& rpath, const
         return proceedToHandler(r, OK);
 
     // Attempt to map a request targeting the main host to an actual file
-    if (isNil(vpath)) {
+    if (isNull(vpath)) {
         const failable<request_rec*> fnr = httpd::internalSubRequest(r->uri, r);
         if (!hasContent(fnr))
             return rcode(fnr);
@@ -1095,7 +1095,7 @@ const int translateRequest(request_rec* const r, const list<value>& rpath, const
 
         // Make sure a document root request ends with a '/' using
         // an external redirect
-        if (isNil(rpath) && r->uri[strlen(r->uri) - 1] != '/') {
+        if (isNull(rpath) && r->uri[strlen(r->uri) - 1] != '/') {
             const string target = string(r->uri) + string("/") + (r->args != NULL? string("?") + string(r->args) : emptyString);
             debug(target, "modeval::translateRequest::location");
             return proceedToHandler(r, httpd::externalRedirect(target, r));
@@ -1128,7 +1128,7 @@ int translate(request_rec *r) {
     const list<value> rpath = pathValues(r->uri);
 
     // Let default handler handle a resource request
-    const string prefix = isNil(rpath)? emptyStringValue : car(rpath);
+    const string prefix = isNull(rpath)? emptyStringValue : car(rpath);
     if (prefix == string("vhosts") || prefix == string("v"))
         return DECLINED;
 
@@ -1137,7 +1137,7 @@ int translate(request_rec *r) {
 
     // If the request is targeting a virtual host, configure the components
     // in that virtual host
-    if (length(sc.vhostc.domain) != 0 && (length(sc.vhostc.contribPath) != 0 || !isNil(sc.vhostc.contributor)) && httpd::isVhostRequest(sc.server, sc.vhostc.domain, r)) {
+    if (length(sc.vhostc.domain) != 0 && (length(sc.vhostc.contribPath) != 0 || !isNull(sc.vhostc.contributor)) && httpd::isVhostRequest(sc.server, sc.vhostc.domain, r)) {
         const string vname = http::subDomain(httpd::hostName(r));
         const failable<Composite> fvcompos = confComponents(sc.vhostc.contribPath, sc.vhostc.composName, sc.vhostc.contributor, vname, reqc.impls, (value)sc.lifecycle, sc.sslc, sc.timeout);
         if (!hasContent(fvcompos))
@@ -1158,7 +1158,7 @@ int translate(request_rec *r) {
         return rc;
 
     // Attempt to map the first segment of the request path to a virtual host
-    if (length(prefix) != 0 && (length(sc.vhostc.contribPath) != 0 || !isNil(sc.vhostc.contributor))) {
+    if (length(prefix) != 0 && (length(sc.vhostc.contribPath) != 0 || !isNull(sc.vhostc.contributor))) {
         const string vname = prefix;
         const failable<Composite> fvcompos = confComponents(sc.vhostc.contribPath, sc.vhostc.composName, sc.vhostc.contributor, vname, reqc.impls, (value)sc.lifecycle, sc.sslc, sc.timeout);
         if (!hasContent(fvcompos))
@@ -1180,7 +1180,7 @@ const int handleRequest(const list<value>& rpath, request_rec* const r, const li
 
     // Get the component implementation lambda
     const list<value> impl(rbtreeAssoc<value>(cadr(rpath), impls));
-    if (isNil(impl)) {
+    if (isNull(impl)) {
         mkfailure<int>(string("Couldn't find component implementation: ") + (string)cadr(rpath));
         return HTTP_NOT_FOUND;
     }
@@ -1233,14 +1233,14 @@ int handler(request_rec* r) {
         debug(redir, "modeval::handler::internalredirect");
         return httpd::internalRedirect(redir, r);
     }
-    if (isNil((const list<value>)reqc.rpath))
+    if (isNull((const list<value>)reqc.rpath))
         return HTTP_NOT_FOUND;
 
     // Get the server configuration
     const ServerConf& sc = httpd::serverConf<ServerConf>(r, &mod_tuscany_eval);
 
     // Handle a request targeting a component in a virtual host
-    if (!isNil((const list<value>)reqc.vpath)) {
+    if (!isNull((const list<value>)reqc.vpath)) {
 
         // Start the components in the virtual host
         const failable<list<value> > fsimpls = startComponents(reqc.impls);
@@ -1280,7 +1280,7 @@ authn_status checkPassword(request_rec* r, const char* u, const char* p) {
 
     // Get the server configuration
     const ServerConf& sc = httpd::serverConf<ServerConf>(r, &mod_tuscany_eval);
-    if (isNil(sc.vhostc.authenticator)) {
+    if (isNull(sc.vhostc.authenticator)) {
         mkfailure<int>("SCA authenticator not configured");
         return AUTH_GENERAL_ERROR;
     }
@@ -1293,9 +1293,9 @@ authn_status checkPassword(request_rec* r, const char* u, const char* p) {
         return AUTH_USER_NOT_FOUND;
     }
     const value hval = content(val);
-    const list<value> hcontent = isList(hval) && !isNil(hval) && isList(car<value>(hval)) && !isNil(car<value>(hval))?  assoc<value>(value("content"), cdr<value>(car<value>(hval))) : nilListValue;
-    const list<value> hassoc = isNil(hcontent)? nilListValue : assoc<value>(value("hash"), cdr<value>(hcontent));
-    if (isNil(hassoc)) {
+    const list<value> hcontent = isList(hval) && !isNull(hval) && isList(car<value>(hval)) && !isNull(car<value>(hval))?  assoc<value>(value("content"), cdr<value>(car<value>(hval))) : nilListValue;
+    const list<value> hassoc = isNull(hcontent)? nilListValue : assoc<value>(value("hash"), cdr<value>(hcontent));
+    if (isNull(hassoc)) {
         mkfailure<int>(string("SCA authentication check user failed, hash not found: ") + user, -1, user != "admin");
         return AUTH_USER_NOT_FOUND;
     }
@@ -1330,10 +1330,10 @@ apr_status_t serverCleanup(void* v) {
     stopComponents(sc.compos.impls);
 
     // Call the module lifecycle function
-    if (isNil((value)sc.lifecycle))
+    if (isNull((value)sc.lifecycle))
         return APR_SUCCESS;
     const lvvlambda ll = (value)sc.lifecycle;
-    if (isNil(ll))
+    if (isNull(ll))
         return APR_SUCCESS;
 
     debug((value)sc.lifecycle, "modeval::serverCleanup::stop");
@@ -1449,7 +1449,7 @@ void childInit(apr_pool_t* p, server_rec* s) {
     // Get the vhost contributor component implementation lambda
     if (length(sc.vhostc.contributorName) != 0) {
         const list<value> impl(rbtreeAssoc<value>((string)sc.vhostc.contributorName, (const list<value>)sc.compos.impls));
-        if (isNil(impl)) {
+        if (isNull(impl)) {
             mkfailure<int>(string("Couldn't find contributor component implementation: ") + sc.vhostc.contributorName);
             failureExitChild();
         }
@@ -1459,7 +1459,7 @@ void childInit(apr_pool_t* p, server_rec* s) {
     // Get the vhost authenticator component implementation lambda
     if (length(sc.vhostc.authenticatorName) != 0) {
         const list<value> impl(rbtreeAssoc<value>((string)sc.vhostc.authenticatorName, (const list<value>)sc.compos.impls));
-        if (isNil(impl)) {
+        if (isNull(impl)) {
             mkfailure<int>(string("Couldn't find authenticator component implementation: ") + sc.vhostc.authenticatorName);
             failureExitChild();
         }
diff --git a/sca-cpp/trunk/modules/server/mod-scheme.hpp b/sca-cpp/trunk/modules/server/mod-scheme.hpp
index 36d91dc904..6a387a0991 100644
--- a/sca-cpp/trunk/modules/server/mod-scheme.hpp
+++ b/sca-cpp/trunk/modules/server/mod-scheme.hpp
@@ -43,7 +43,7 @@ namespace modscheme {
  * Convert proxy lambdas to evaluator primitive procedures.
  */
 const list<value> primitiveProcedures(const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons<value>(mklist<value>(scheme::primitiveSymbol, car(l)), primitiveProcedures(cdr(l)));
 }
@@ -58,7 +58,7 @@ const failable<lvvlambda > evalImplementation(const string& path, const value& i
     if (fail(is))
         return mkfailure<lvvlambda >(string("Could not read implementation: ") + fpath);
     const value script = scheme::readScript(is);
-    if (isNil(script))
+    if (isNull(script))
         return mkfailure<lvvlambda >(string("Could not read implementation: ") + fpath);
     const list<value> pxproc = scheme::quotedParameters(primitiveProcedures(px));
 
@@ -68,7 +68,7 @@ const failable<lvvlambda > evalImplementation(const string& path, const value& i
         debug(expr, "modeval::scheme::applyImplementation::input");
         scheme::Env env = scheme::setupEnvironment();
         const value res = scheme::evalScript(expr, script, env);
-        const value val = isNil(res)? mklist<value>(nilValue, string("Could not evaluate expression")) : mklist<value>(res);
+        const value val = isNull(res)? mklist<value>(nilValue, string("Could not evaluate expression")) : mklist<value>(res);
         debug(val, "modeval::scheme::applyImplementation::result");
         return val;
     };
diff --git a/sca-cpp/trunk/modules/wsgi/atomutil.py b/sca-cpp/trunk/modules/wsgi/atomutil.py
index 4b67ef216e..d65b26c41c 100644
--- a/sca-cpp/trunk/modules/wsgi/atomutil.py
+++ b/sca-cpp/trunk/modules/wsgi/atomutil.py
@@ -24,23 +24,23 @@ from xmlutil import *
 # Convert a list of elements to a list of values representing an ATOM entry
 def entryElementValues(e):
     lt = filter(selector((element, "'title")), e)
-    t = "" if isNil(lt) else elementValue(car(lt))
+    t = "" if isNull(lt) else elementValue(car(lt))
     li = filter(selector((element, "'id")), e)
-    i = "" if isNil(li) else elementValue(car(li))
+    i = "" if isNull(li) else elementValue(car(li))
     lc = filter(selector((element, "'content")), e)
     return append((element, "'entry", (element, "'title", t), (element, "'id", i)),
-            () if isNil(lc) else () if isAttribute(elementValue(car(lc))) else ((element, "'content", elementValue(car(lc))),))
+            () if isNull(lc) else () if isAttribute(elementValue(car(lc))) else ((element, "'content", elementValue(car(lc))),))
 
 # Convert a list of elements to a list of values representing ATOM entries
 def entriesElementValues(e):
-    if isNil(e):
+    if isNull(e):
         return e
     return cons(entryElementValues(car(e)), entriesElementValues(cdr(e)))
 
 # Convert a list of strings to a list of values representing an ATOM entry
 def readATOMEntry(l):
     e = readXML(l)
-    if isNil(e):
+    if isNull(e):
         return ()
     return (entryElementValues(car(e)),)
 
@@ -59,7 +59,7 @@ def isATOMEntry(l):
 # Convert a list of strings to a list of values representing an ATOM feed
 def readATOMFeed(l):
     f = readXML(l)
-    if isNil(f):
+    if isNull(f):
         return ()
     t = filter(selector((element, "'title")), car(f))
     i = filter(selector((element, "'id")), car(f))
@@ -73,44 +73,44 @@ def entryElement(l):
     title = elementValue(namedElementChild("'title", l))
     id = elementValue(namedElementChild("'id", l))
     content = namedElementChild("'content", l)
-    text = False if isNil(content) else elementHasValue(content)
+    text = False if isNull(content) else elementHasValue(content)
     return append(append(
             (element, "'entry", (attribute, "'xmlns", "http://www.w3.org/2005/Atom"),
              (element, "'title", (attribute, "'type", "text"), title),
              (element, "'id", id)),
-            () if isNil(content) else (append(
+            () if isNull(content) else (append(
                 (element, "'content", (attribute, "'type", "text" if text else "application/xml")), (elementValue(content),) if text else elementChildren(content)),)),
             ((element, "'link", (attribute, "'href", id)),))
 
 # Convert a list of values representing ATOM entries to a list of elements
 def entriesElements(l):
-    if isNil(l):
+    if isNull(l):
         return l
     return cons(entryElement(car(l)), entriesElements(cdr(l)))
 
 # Convert a list of values representing an ATOM entry to an ATOM entry
 def writeATOMEntry(ll):
-    l = ll if isNil(ll) else car(ll)
+    l = ll if isNull(ll) else car(ll)
     return writeXML((entryElement(l),), True)
 
 # Convert a list of values representing an ATOM feed to an ATOM feed
 def writeATOMFeed(ll):
-    l = ll if isNil(ll) else car(ll)
+    l = ll if isNull(ll) else car(ll)
     lt = filter(selector((element, "'title")), l)
-    t = '' if isNil(lt) else elementValue(car(lt))
+    t = '' if isNull(lt) else elementValue(car(lt))
     li = filter(selector((element, "'id")), l)
-    i = '' if isNil(li) else elementValue(car(li))
+    i = '' if isNull(li) else elementValue(car(li))
     f = (element, "'feed", (attribute, "'xmlns", "http://www.w3.org/2005/Atom"),
             (element, "'title", (attribute, "'type", "text"), t),
             (element, "'id", i))
 
     # Write ATOM entries
     le = filter(selector((element, "'entry")), l)
-    if isNil(le):
+    if isNull(le):
         return writeXML((f,), True)
 
     # Write a single ATOM entry element with a list of values
-    if not isNil(le) and not isNil(car(le)) and isList(car(caddr(car(le)))):
+    if not isNull(le) and not isNull(car(le)) and isList(car(caddr(car(le)))):
         fe = append(f, entriesElements(caddr(car(le))))
         return writeXML((fe,), True)
 
diff --git a/sca-cpp/trunk/modules/wsgi/composite.py b/sca-cpp/trunk/modules/wsgi/composite.py
index 77f2ecdb59..fbec66dc33 100755
--- a/sca-cpp/trunk/modules/wsgi/composite.py
+++ b/sca-cpp/trunk/modules/wsgi/composite.py
@@ -59,7 +59,7 @@ def requestIfNoneMatch(e):
 
 # Hash a list of strings into an MD5 signature
 def md5update(md, s):
-    if isNil(s):
+    if isNull(s):
         return md.hexdigest()
     md.update(car(s))
     return md5update(md, cdr(s))
@@ -113,7 +113,7 @@ def fileresult(e, r, ct, f):
 
 # Converts the args received in a POST to a list of key value pairs
 def postArgs(a):
-    if isNil(a):
+    if isNull(a):
         return ((),)
     l = car(a);
     return cons(l, postArgs(cdr(a)))
@@ -188,16 +188,16 @@ def application(e, r):
             return result(e, r, 200, (("Content-type", "application/json"),), writeJSON(()))
 
         # Write content-type / content-list pair
-        if isString(car(v)) and not isNil(cdr(v)) and isList(cadr(v)):
+        if isString(car(v)) and not isNull(cdr(v)) and isList(cadr(v)):
             return result(e, r, 200, (("Content-type", car(v)),), cadr(v))
         
         # Convert list of values to element values
         ve = valuesToElements(v)
 
         # Write an assoc result as a JSON value
-        if isList(car(ve)) and not isNil(car(ve)):
+        if isList(car(ve)) and not isNull(car(ve)):
             el = car(ve)
-            if isSymbol(car(el)) and car(el) == element and not isNil(cdr(el)) and isSymbol(cadr(el)):
+            if isSymbol(car(el)) and car(el) == element and not isNull(cdr(el)) and isSymbol(cadr(el)):
                 if cadr(el) == "'feed":
                     return result(e, r, 200, (("Content-type", "application/atom+xml"),), writeATOMFeed(ve))
                 if cadr(el) == "'entry":
@@ -224,7 +224,7 @@ def application(e, r):
         if contains(ct, "application/atom+xml"):
             ae = elementsToValues(readATOMEntry(requestBody(e)))
             v = comp("post", id, ae)
-            if isNil(v):
+            if isNull(v):
                 return failure(e, r, 500)
             return result(e, r, 201, (("Location", request_uri(e) + "/" + "/".join(v)),))
         return failure(e, r, 500)
diff --git a/sca-cpp/trunk/modules/wsgi/elemutil.py b/sca-cpp/trunk/modules/wsgi/elemutil.py
index 00b76c5c6e..bb176e7ffe 100644
--- a/sca-cpp/trunk/modules/wsgi/elemutil.py
+++ b/sca-cpp/trunk/modules/wsgi/elemutil.py
@@ -25,13 +25,13 @@ atsign = "'@"
 
 # Return true if a value is an element
 def isElement(v):
-    if not isList(v) or isNil(v) or v == None or car(v) != element:
+    if not isList(v) or isNull(v) or v == None or car(v) != element:
         return False
     return True
 
 # Return true if a value is an attribute
 def isAttribute(v):
-    if not isList(v) or isNil(v) or v == None or car(v) != attribute:
+    if not isList(v) or isNull(v) or v == None or car(v) != attribute:
         return False
     return True
 
@@ -49,7 +49,7 @@ def elementName(l):
 
 # Return true if an element has children
 def elementHasChildren(l):
-    return not isNil(cddr(l))
+    return not isNull(cddr(l))
 
 # Return the children of an element
 def elementChildren(l):
@@ -60,7 +60,7 @@ def elementHasValue(l):
     r = reverse(l)
     if isSymbol(car(r)):
         return False
-    if isList(car(r)) and not isNil(car(r)) and isSymbol(car(car(r))):
+    if isList(car(r)) and not isNull(car(r)) and isSymbol(car(car(r))):
         return False
     return True
 
@@ -72,7 +72,7 @@ def elementValue(l):
 def elementToValueIsList(v):
     if not isList(v):
         return False
-    return isNil(v) or not isSymbol(car(v))
+    return isNull(v) or not isSymbol(car(v))
 
 def elementToValue(t):
     if isTaggedList(t, attribute):
@@ -91,14 +91,14 @@ def elementToValue(t):
 def elementToValueIsSymbol(v):
     if not isList(v):
         return False
-    if (isNil(v)):
+    if (isNull(v)):
         return False
     if not isSymbol(car(v)):
         return False
     return True
 
 def elementToValueGroupValues(v, l):
-    if isNil(l) or not elementToValueIsSymbol(v) or not elementToValueIsSymbol(car(l)):
+    if isNull(l) or not elementToValueIsSymbol(v) or not elementToValueIsSymbol(car(l)):
         return cons(v, l)
     if car(car(l)) != car(v):
         return cons(v, l)
@@ -109,20 +109,20 @@ def elementToValueGroupValues(v, l):
     return elementToValueGroupValues(g, cdr(l))
 
 def elementsToValues(e):
-    if isNil(e):
+    if isNull(e):
         return e
     return elementToValueGroupValues(elementToValue(car(e)), elementsToValues(cdr(e)))
 
 # Convert a value to an element
 def valueToElement(t):
-    if isList(t) and not isNil(t) and isSymbol(car(t)):
+    if isList(t) and not isNull(t) and isSymbol(car(t)):
         n = car(t)
-        v = () if isNil(cdr(t)) else cadr(t)
+        v = () if isNull(cdr(t)) else cadr(t)
         if not isList(v):
             if n[0:2] == atsign:
                 return (attribute, "'" + n[2:], v)
             return (element, n, v)
-        if isNil(v) or not isSymbol(car(v)):
+        if isNull(v) or not isSymbol(car(v)):
             return cons(element, cons(n, (valuesToElements(v),)))
         return cons(element, cons(n, valuesToElements(cdr(t))))
     if not isList(t):
@@ -131,15 +131,15 @@ def valueToElement(t):
 
 # Convert a list of values to a list of elements
 def valuesToElements(l):
-    if isNil(l):
+    if isNull(l):
         return l
     return cons(valueToElement(car(l)), valuesToElements(cdr(l)))
 
 # Return a selector lambda function which can be used to filter elements
 def evalSelect(s, v):
-    if isNil(s):
+    if isNull(s):
         return True
-    if isNil(v):
+    if isNull(v):
         return False
     if car(s) != car(v):
         return False
@@ -151,7 +151,7 @@ def selector(s):
 # Return the value of the attribute with the given name
 def namedAttributeValue(name, l):
     f = filter(lambda v: isAttribute(v) and attributeName(v) == name, l)
-    if isNil(f):
+    if isNull(f):
         return None
     return caddr(car(f))
 
@@ -162,7 +162,7 @@ def namedElementChildren(name, l):
 # Return the child element with the given name
 def namedElementChild(name, l):
     f = namedElementChildren(name, l)
-    if isNil(f):
+    if isNull(f):
         return None
     return car(f)
 
diff --git a/sca-cpp/trunk/modules/wsgi/jsonutil.py b/sca-cpp/trunk/modules/wsgi/jsonutil.py
index 849b44405b..f284fd1a89 100644
--- a/sca-cpp/trunk/modules/wsgi/jsonutil.py
+++ b/sca-cpp/trunk/modules/wsgi/jsonutil.py
@@ -28,19 +28,19 @@ from elemutil import *
 
 # Return true if a list represents a JS array
 def isJSArray(l):
-    if isNil(l):
+    if isNull(l):
         return True
     v = car(l)
     if isSymbol(v):
         return False
     if isList(v):
-        if not isNil(v) and isSymbol(car(v)):
+        if not isNull(v) and isSymbol(car(v)):
             return False
     return True
 
 # Converts JSON properties to values
 def jsPropertiesToValues(propertiesSoFar, o, i):
-    if isNil(i):
+    if isNull(i):
         return propertiesSoFar
     p = car(i)
     jsv = o[p]
@@ -69,7 +69,7 @@ def jsValToValue(jsv):
 
 # Return true if a list of strings contains a JSON document
 def isJSON(l):
-    if isNil(l):
+    if isNull(l):
         return False
     s = car(l)[0:1]
     return s == "[" or s == "{"
@@ -83,7 +83,7 @@ def readJSON(l):
 
 # Convert a list of values to JSON array elements
 def valuesToJSElements(a, l, i):
-    if isNil(l):
+    if isNull(l):
         return a
     pv = valueToJSVal(car(l))
     a[i] = pv
@@ -99,7 +99,7 @@ def valueToJSVal(v):
 
 # Convert a list of values to JSON properties
 def valuesToJSProperties(o, l):
-    if isNil(l):
+    if isNull(l):
         return o
     token = car(l)
     if isTaggedList(token, attribute):
diff --git a/sca-cpp/trunk/modules/wsgi/rssutil.py b/sca-cpp/trunk/modules/wsgi/rssutil.py
index 984d71b690..c1b326c82d 100644
--- a/sca-cpp/trunk/modules/wsgi/rssutil.py
+++ b/sca-cpp/trunk/modules/wsgi/rssutil.py
@@ -24,22 +24,22 @@ from xmlutil import *
 # Convert a list of elements to a list of values representing an RSS entry
 def entryElementsToValues(e):
     lt = filter(selector((element, "'title")), e)
-    t = "" if isNil(lt) else elementValue(car(lt))
+    t = "" if isNull(lt) else elementValue(car(lt))
     li = filter(selector((element, "'link")), e)
-    i = "" if isNil(li) else elementValue(car(li))
+    i = "" if isNull(li) else elementValue(car(li))
     lc = filter(selector((element, "'description")), e)
     return (t, i, elementValue(car(lc)))
 
 # Convert a list of elements to a list of values representing RSS entries
 def entriesElementsToValues(e):
-    if isNil(e):
+    if isNull(e):
         return e
     return cons(entryElementsToValues(car(e)), entriesElementsToValues(cdr(e)))
 
 # Convert a list of strings to a list of values representing an RSS entry
 def readRSSEntry(l):
     e = readXML(l)
-    if isNil(e):
+    if isNull(e):
         return ()
     return entryElementsToValues(car(e))
 
@@ -57,19 +57,19 @@ def isRSSFeed(l):
 # Convert a list of strings to a list of values representing an RSS feed
 def readRSSFeed(l):
     f = readXML(l)
-    if isNil(f):
+    if isNull(f):
         return ()
     c = filter(selector((element, "'channel")), car(f))
     t = filter(selector((element, "'title")), car(c))
     i = filter(selector((element, "'link")), car(c))
     e = filter(selector((element, "'item")), car(c))
-    if isNil(e):
+    if isNull(e):
         return (elementValue(car(t)), elementValue(car(i)))
     return cons(elementValue(car(t)), cons(elementValue(car(i)), entriesElementsToValues(e)))
 
 # Convert an RSS feed containing elements to an RSS feed containing values
 def feedValuesLoop(e):
-    if (isNil(e)):
+    if (isNull(e)):
         return e
     return cons(entryValue(car(e)), feedValuesLoop(cdr(e)))
 
@@ -85,7 +85,7 @@ def entryElement(l):
 
 # Convert a list of values representing RSS entries to a list of elements
 def entriesElements(l):
-    if isNil(l):
+    if isNull(l):
         return l
     return cons(entryElement(car(l)), entriesElements(cdr(l)))
 
@@ -98,7 +98,7 @@ def writeRSSFeed(l):
     c = ((element, "'title", car(l)),
             (element, "'link", cadr(l)),
             (element, "'description", car(l)))
-    ce = c if isNil(cddr(l)) else append(c, entriesElements(cddr(l)))
+    ce = c if isNull(cddr(l)) else append(c, entriesElements(cddr(l)))
     fe = (element, "'rss", (attribute, "'version", "2.0"), append((element, "'channel"), ce))
     return writeXML((fe,), True)
 
@@ -108,7 +108,7 @@ def entryValuesToElements(v):
 
 # Convert an RSS feed containing values to an RSS feed containing elements
 def feedValuesToElementsLoop(v):
-    if isNil(v):
+    if isNull(v):
         return v
     return cons(entryValuesToElements(car(v)), feedValuesToElementsLoop(cdr(v)))
 
diff --git a/sca-cpp/trunk/modules/wsgi/util.py b/sca-cpp/trunk/modules/wsgi/util.py
index f630455901..97931c0c09 100644
--- a/sca-cpp/trunk/modules/wsgi/util.py
+++ b/sca-cpp/trunk/modules/wsgi/util.py
@@ -57,9 +57,9 @@ def reverse(l):
     r.reverse()
     return tuple(r)
 
-def isNil(l):
+def isNull(l):
     if isinstance(l, streampair):
-        return l.isNil()
+        return l.isNull()
     return l is None or l == ()
 
 def isSymbol(v):
@@ -76,7 +76,7 @@ def isList(v):
     return True
 
 def isTaggedList(v, t):
-    return isList(v) and not isNil(v) and car(v) == t
+    return isList(v) and not isNull(v) and car(v) == t
 
 
 # Scheme-like streams
@@ -88,7 +88,7 @@ class streampair(object):
     def __repr__(self):
         return repr(self[0:len(self)])
 
-    def isNil(self):
+    def isNull(self):
         return self.cdr == ()
 
     def __len__(self):
@@ -102,7 +102,7 @@ class streampair(object):
         return self.cdr()[i - 1]
 
     def __getslice__(self, i, j):
-        if isNil(self):
+        if isNull(self):
             return ()
         if i > 0:
             if j == maxint:
@@ -156,7 +156,7 @@ def curry(f, *args):
 
 # Convert a path represented as a list of values to a string
 def path(p):
-    if isNil(p):
+    if isNull(p):
         return ""
     return "/" + car(p) + path(cdr(p))
 
diff --git a/sca-cpp/trunk/modules/wsgi/xmlutil.py b/sca-cpp/trunk/modules/wsgi/xmlutil.py
index 83b1cf2f92..bc1a1b376a 100644
--- a/sca-cpp/trunk/modules/wsgi/xmlutil.py
+++ b/sca-cpp/trunk/modules/wsgi/xmlutil.py
@@ -46,7 +46,7 @@ def readElements(l):
 
 # Return true if a list of strings represents an XML document
 def isXML(l):
-    if isNil(l):
+    if isNull(l):
         return False
     if car(l)[0:5] != "<?xml":
         return False
@@ -86,12 +86,12 @@ def readXML(l):
 
 # Write a list of XML element and attribute tokens
 def expandElementValues(n, l):
-    if isNil(l):
+    if isNull(l):
         return l
     return cons(cons(element, cons(n, car(l))), expandElementValues(n, cdr(l)))
 
 def writeList(l, xml):
-    if isNil(l):
+    if isNull(l):
         return xml
     token = car(l)
     if isTaggedList(token, attribute):
diff --git a/sca-cpp/trunk/modules/xml/xml.hpp b/sca-cpp/trunk/modules/xml/xml.hpp
index 0a04d5f90a..70747e2157 100644
--- a/sca-cpp/trunk/modules/xml/xml.hpp
+++ b/sca-cpp/trunk/modules/xml/xml.hpp
@@ -192,7 +192,7 @@ inline const value readToken(XMLReader& reader) {
  */
 inline const list<value> readList(const list<value>& listSoFar, XMLReader& reader) {
     const value token = readToken(reader);
-    if(isNil(token) || endElement == token)
+    if(isNull(token) || endElement == token)
         return reverse(listSoFar);
     if(startElement == token)
         return readList(cons<value>(readList(mklist(element), reader), listSoFar), reader);
@@ -225,7 +225,7 @@ public:
  */
 inline int readCallback(void *context, char* buffer, int len) {
     XMLReadContext& rc = *(XMLReadContext*)context;
-    if (isNil((const list<string>)rc.ilist))
+    if (isNull((const list<string>)rc.ilist))
         return 0;
     const list<string> f(fragment(rc.ilist, len));
     const string s(car(f));
@@ -238,7 +238,7 @@ inline int readCallback(void *context, char* buffer, int len) {
  * Return true if a list of strings contains an XML document.
  */
 inline const bool isXML(const list<string>& ls) {
-    if (isNil(ls))
+    if (isNull(ls))
         return false;
     return substr(car(ls), 0, 5) == "<?xml";
 }
@@ -266,13 +266,13 @@ const char* const encoding = "UTF-8";
  * Write a list of XML element or attribute tokens.
  */
 inline const list<value> expandElementValues(const value& n, const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons<value>(value(cons<value>(element, cons<value>(n, isList(car(l))? (list<value>)car(l) : mklist(car(l))))), expandElementValues(n, cdr(l)));
 }
 
 inline const failable<bool> writeList(const list<value>& l, const xmlTextWriterPtr xml) {
-    if (isNil(l))
+    if (isNull(l))
         return true;
 
     // Write an attribute
diff --git a/sca-cpp/trunk/samples/store-cpp/shopping-cart.cpp b/sca-cpp/trunk/samples/store-cpp/shopping-cart.cpp
index e65aa0d392..46b032af94 100644
--- a/sca-cpp/trunk/samples/store-cpp/shopping-cart.cpp
+++ b/sca-cpp/trunk/samples/store-cpp/shopping-cart.cpp
@@ -45,7 +45,7 @@ const list<value> getcart(const value& id, const lvvlambda& cache) {
     cerr << "cart fvalue: " << fcart << "\n";
     cerr << "cart content: " << content(fcart) << "\n";
     cerr << "cart reason: " << reason(fcart) << "\n";
-    if (isNil(cart))
+    if (isNull(cart))
         return value(nilListValue);
     return (list<value>)cart;
 }
@@ -65,7 +65,7 @@ const failable<value> post(unused const list<value>& collection, const value& it
  * Find an item in the cart.
  */
 const value find(const value& id, const list<value>& cart) {
-    if (isNil(cart))
+    if (isNull(cart))
         return mklist<value>(mklist<value>("entry", mklist<value>("title", string("Item")), mklist<value>("id", "0")));
     if (id == cadr<value>(caddr<value>(car(cart))))
         return mklist<value>(car(cart));
@@ -76,7 +76,7 @@ const value find(const value& id, const list<value>& cart) {
  * Return items from the cart.
  */
 const failable<value> get(const list<value>& id, const lvvlambda& cache) {
-    if (isNil(id))
+    if (isNull(id))
         return value(mklist<value>(append(mklist<value>("feed", mklist<value>("title", string("Your Cart")), mklist<value>("id", cartId)), getcart(cartId, cache))));
     return find(car(id), getcart(cartId, cache));
 }
@@ -85,7 +85,7 @@ const failable<value> get(const list<value>& id, const lvvlambda& cache) {
  * Delete items from the cart.
  */
 const failable<value> del(const list<value>& id, unused const lvvlambda& cache) {
-    if (isNil(id))
+    if (isNull(id))
         return cache(mklist<value>("delete", mklist<value>(cartId)));
     return trueValue;
 }
@@ -101,7 +101,7 @@ const double price(const list<value>& item) {
  * Sum the prices of a list of items.
  */
 const double sum(const list<value>& items) {
-    if (isNil(items))
+    if (isNull(items))
         return 0;
     return price(car(items)) + sum(cdr(items));
 }
diff --git a/sca-cpp/trunk/samples/store-java/store/ShoppingCartImpl.java b/sca-cpp/trunk/samples/store-java/store/ShoppingCartImpl.java
index bd7678cce7..b5329606d1 100644
--- a/sca-cpp/trunk/samples/store-java/store/ShoppingCartImpl.java
+++ b/sca-cpp/trunk/samples/store-java/store/ShoppingCartImpl.java
@@ -58,7 +58,7 @@ public class ShoppingCartImpl {
      * Find an item in the cart.
      */
     Iterable<?> find(final String id, final Iterable<?> cart) {
-        if(isNil(cart))
+        if(isNull(cart))
             return list(list("'entry", list("'title", "Item"), list("'id", "0")));
         if(id.equals(cadr(caddr(car(cart)))))
             return list(car(cart));
@@ -69,7 +69,7 @@ public class ShoppingCartImpl {
      * Return items from the cart.
      */
     public Iterable<?> get(final Iterable<String> id, final Service cache) {
-        if(isNil(id))
+        if(isNull(id))
             return list(append(list("'feed", list("'title", "Your Cart"), list("'id", cartId)), this.getcart(cartId, cache)));
         return this.find((String)car(id), this.getcart(cartId, cache));
     }
@@ -78,7 +78,7 @@ public class ShoppingCartImpl {
      * Delete items from the cart.
      */
     public Boolean delete(final Iterable<String> id, final Service cache) {
-        if(isNil(id)) {
+        if(isNull(id)) {
             final Iterable<String> iid = list(cartId);
             return cache.delete(iid);
         }
@@ -97,7 +97,7 @@ public class ShoppingCartImpl {
      * Sum the prices of a list of items.
      */
     Double sum(final Iterable<?> items) {
-        if(isNil(items))
+        if(isNull(items))
             return 0.0;
         return this.price((Iterable<?>)car(items)) + this.sum(cdr(items));
     }