CMS Made Simple Forums

JM_Forum is currently being worked on to be ready for CMSMS 2.x. There should be just a few minor changes needed but I didn't have time to look at it yet. There may be a new version out soon.
Just a note: it is a simple minimal forum script, not a full fledged forum, mainly because a lot of functions other forum scripts can provide are already implemented either in the core or by 3rd party modules.

Currently that is the only forum module under active development. Other options may be trying to integrate external forum scripts, in which case you can choose any one that you fell comfortable with, but the only level of integration you'll achieve without a bit of coding is just visual... users, content and features will be separated. While in some applications that shouldn't be an issue, having all integrated is usually nicer of course.
I can't give you an actual time frame for completing next release, but it should be rather soon as, for the most part, the module is working (in its svn trunk version) with just a bug or two. Current state of the trunk shouldn't be used in production sites though.