GateIn is not the legacy JBoss portal so i'm not sure if JBoss Forum works on it. By the way, if JBoss Forum is a portlet and is not tightly coupled with legacy JBoss portal, there is big chance that it could run on GateIn.
It seems to me it is tightly coupled with JBoss Portal but I figured since GateIn was a mashup it might just work. I tried to deploy it on GateIn but I had no luck. Maybe someone knows of other forums or bullentin boards or message boards that might work will with GateIn? Or other suggestions for JBoss Forums?