netbeans-devel cannot start more than once.
If started, it is very unstable.

Fix: patchfile to put to files-directory is attached to PR.
Patch for Makefile is below the line as follows:
========================================================

-- Makefile    2011-10-27 11:00:06.000000000 +0200
+++ Makefile    2012-01-03 08:42:32.000000000 +0100
@@ -29,11 +29,13 @@
 do-patch:
        @${REINPLACE_CMD} -i "" -e '19s|#||;19s|/path/to/jdk|${JAVA_HOME}|' \
            ${WRKSRC}/etc/netbeans.conf
+       @${PATCH} -s <${PATCHDIR}/freebsd-support.patch

 do-install:
        @${MKDIR} ${PREFIXDIR}
        @(cd ${WRKSRC} && ${COPYTREE_SHARE} \* ${PREFIXDIR})
        @${CHMOD} ${BINMODE} ${PREFIXDIR}/bin/netbeans
+       @${CHMOD} ${BINMODE} ${PREFIXDIR}/java/maven/bin/mvn
        @${LN} -sf ${PREFIXDIR}/bin/netbeans ${PREFIX}/bin/netbeans-${PORTVERSION}

 .include <bsd.port.mk>



Patch attached with submission follows:
How-To-Repeat: just install netbeans-devel and try to use it.