I started the development of Rubia Forums. It's the old Jboss Forums project resumed and refactored with the new java enterprise technologies. Another feature respect the previous version is that it doesn't depend by the platform (JBoss Portal) but it can be installed in more environments (Actually in jboss 7 standalone and Gatein 3.6).
Here the sources.
Here a demo version installed in Gatein. You can log using the default accounts of Gatein:
root/gtn
john/gtn
mary/gtn
demo/gtn
Soon I will do a new homepage that it will substitute the old.