diff -r b922e98fdfa8 apisupport.harness/release/README
--- a/apisupport.harness/release/README	Fri Jun 27 10:48:07 2014 +0200
+++ b/apisupport.harness/release/README	Mon Jul 14 12:02:28 2014 +0200
@@ -688,6 +688,9 @@
 
 javac.target - default ${javac.source}; controls version of generated bytecode
 
+javac.fork - default "false"; one can request the complication to be done
+in a separate process. Useful for large code bases.
+
 javadoc.apichanges - optional location of an API changes list. Currently for
 netbeans.org modules only.
 
diff -r b922e98fdfa8 j2ee.dd/nbproject/project.properties
--- a/j2ee.dd/nbproject/project.properties	Fri Jun 27 10:48:07 2014 +0200
+++ b/j2ee.dd/nbproject/project.properties	Mon Jul 14 12:02:28 2014 +0200
@@ -41,6 +41,7 @@
 # made subject to such option by the copyright holder.
 
 javac.source=1.6
+javac.fork=true
 spec.version.base=1.39.0
 is.autoload=true
 
diff -r b922e98fdfa8 nbbuild/antsrc/org/netbeans/nbbuild/CustomJavac.java
--- a/nbbuild/antsrc/org/netbeans/nbbuild/CustomJavac.java	Fri Jun 27 10:48:07 2014 +0200
+++ b/nbbuild/antsrc/org/netbeans/nbbuild/CustomJavac.java	Mon Jul 14 12:02:28 2014 +0200
@@ -80,7 +80,7 @@
 
     private String maybeFork;
     @Override public void setFork(boolean f) {
-        throw new UnsupportedOperationException();
+        super.setFork(f);
     }
     @Override public void setExecutable(String forkExec) {
         maybeFork = forkExec;
diff -r b922e98fdfa8 nbbuild/templates/common.xml
--- a/nbbuild/templates/common.xml	Fri Jun 27 10:48:07 2014 +0200
+++ b/nbbuild/templates/common.xml	Mon Jul 14 12:02:28 2014 +0200
@@ -213,8 +213,11 @@
         <depend srcdir="${src.dir}" destdir="${build.classes.dir}" cache="${build.dir}/depcache">
             <classpath refid="cp"/>
         </depend>
+        <property name="javac.fork" value="false"/>
         <nb-javac srcdir="${src.dir}" destdir="${build.classes.dir}" debug="${build.compiler.debug}" debuglevel="${build.compiler.debuglevel}" encoding="UTF-8"
-                  deprecation="${build.compiler.deprecation}" optimize="${build.compiler.optimize}" source="${javac.source}" target="${javac.target}" includeantruntime="false">
+                  deprecation="${build.compiler.deprecation}" optimize="${build.compiler.optimize}" source="${javac.source}" target="${javac.target}" includeantruntime="false"
+                  fork="${javac.fork}"
+        >
             <classpath refid="cp"/>
             <compilerarg line="${javac.compilerargs}"/>
             <processorpath refid="processor.cp"/>