--- a/apisupport.project/src/org/netbeans/modules/apisupport/project/universe/ModuleList.java	
+++ a/apisupport.project/src/org/netbeans/modules/apisupport/project/universe/ModuleList.java	
@@ -1175,6 +1175,7 @@ 
         Map<String,String> clusterDefs = clusterPropertiesFiles.get(nbroot);
         if (clusterDefs == null) {
             PropertyProvider pp = loadPropertiesFile(new File(nbroot, "nbbuild" + File.separatorChar + "cluster.properties")); // NOI18N
+            // XXX add contrib/contrib-modules.properties
             PropertyEvaluator clusterEval = PropertyUtils.sequentialPropertyEvaluator(
                     PropertyUtils.fixedPropertyProvider(Collections.<String,String>emptyMap()), pp);
             clusterDefs = clusterEval.getProperties();
--- a/nbbuild/antsrc/org/netbeans/nbbuild/CheckModuleConfigs.java	
+++ a/nbbuild/antsrc/org/netbeans/nbbuild/CheckModuleConfigs.java	
@@ -92,6 +92,7 @@ 
         }
         File buildPropertiesFile = new File(nbroot, "nbbuild" + File.separatorChar + "build.properties");
         File clusterPropertiesFile = new File(nbroot, "nbbuild" + File.separatorChar + "cluster.properties");
+        // XXX add contrib/contrib-modules.properties
         File goldenFile = new File(nbroot, "nbbuild" + File.separatorChar + "build" + File.separatorChar + "generated" + File.separatorChar + "moduleconfigs.txt");
         @SuppressWarnings("unchecked")
         Map<String,String> properties = getProject().getProperties();
--- a/nbbuild/antsrc/org/netbeans/nbbuild/ModuleListParser.java	
+++ a/nbbuild/antsrc/org/netbeans/nbbuild/ModuleListParser.java	
@@ -196,6 +196,7 @@ 
                 Map<File,Long[]> timestampsAndSizes = new HashMap<File,Long[]>();
                 registerTimestampAndSize(new File(root, "nbbuild" + File.separatorChar + "cluster.properties"), timestampsAndSizes);
                 registerTimestampAndSize(new File(root, "nbbuild" + File.separatorChar + "build.properties"), timestampsAndSizes);
+                // XXX add contrib/contrib-modules.properties
                 registerTimestampAndSize(new File(root, "nbbuild" + File.separatorChar + "user.build.properties"), timestampsAndSizes);
                 if (doFastScan) {
                     if (project != null) {
--- a/nbbuild/build.properties	
+++ a/nbbuild/build.properties	
@@ -269,6 +269,7 @@ 
     contrib/core.registry,\
     contrib/convertor,\
     nbjunit
+# XXX move contrib/* to contrib/contrib-modules.properties
 
 # List of old and deprecated APIs for building complete javadoc
 
--- a/nbbuild/build.xml	
+++ a/nbbuild/build.xml	
@@ -65,6 +65,7 @@ 
   <target name="all-nozip" depends="build-nozip,commit-validation" description="Build the IDE (no ZIP file, unpacked) and run basic validation tests."/>
 
   <target name="-load-build-properties">
+    <!-- XXX add contrib/contrib-modules.properties -->
     <property file="build.properties"/>
   </target>
 
--- a/nbbuild/cluster.properties	
+++ a/nbbuild/cluster.properties	
@@ -245,6 +245,7 @@ 
         nb.cluster.apisupport
 nb.cluster.testtools=\
         contrib/jemmysupport
+# XXX move contrib/* to contrib/contrib-modules.properties
 
 nb.cluster.ide.dir=ide11
 nb.cluster.ide.depends=nb.cluster.platform
--- a/nbbuild/default-properties.xml	
+++ a/nbbuild/default-properties.xml	
@@ -53,6 +53,7 @@ 
   <property name="build.sysclasspath" value="ignore"/>
 
   <property name="clusters.list.file" location="${nb_all}/nbbuild/cluster.properties"/>
+  <!-- XXX add contrib/contrib-modules.properties -->
   <property name="netbeans.dest.dir" location="${nb_all}/nbbuild/netbeans"/>
   <property name="netbeans.build.dir" location="${nb_all}/nbbuild/build"/>
   <property name="netbeans.javadoc.dir" location="${netbeans.build.dir}/javadoc"/>
--- a/nbbuild/javadoctools/template.xml	
+++ a/nbbuild/javadoctools/template.xml	
@@ -149,6 +149,7 @@ 
         </selector>
         <property name="javadoc.files" value="all-java-files" />
         
+        <!-- XXX add contrib/contrib-modules.properties -->
         <property file="../build.properties" />
 
         <condition property="javadoc.reference.generated" >
--- a/nbbuild/monitor.xml	
+++ a/nbbuild/monitor.xml	
@@ -83,6 +83,7 @@ 
     <property file="user.build.properties"/>
 
     <!-- Read standard property file -->
+    <!-- XXX add contrib/contrib-modules.properties -->
     <property file="build.properties"/>
 
     <!-- Define modules. -->