Mono has always been developed on mailing lists like pretty much every other classic open source project. But many of our younger or migrating users are more used to Web-based forums and have always wanted to have a forum-like interface for the Mono mailing lists.
Thomas Wiest and Joseph Hill have just finished the integration Nabble into the Mono web site. Now people can access all of the Mono mailing lists with a Forums UI.
Messages posted in the forum will go to the appropriate mailing list (either hosted at lists.ximian.com or groups.google.com), and messages posted on the mailing lists get reflected on the forums.
You can access the forums http://www.go-mono.com/forums here.