OK, there are three things that are cool out there that we can use on web sites. They are:
Forum or BBS Software
CMS (Content Management System) Software
and Blog software.
There are two leading BBS packages, SMF and PHPBB and it seems to me that SMF is better. Here is why. If you want to get sophisticated and extreme, you might want to have both a CMS and a forum system on one site. But then you have two databases and a visitor might have to sign up for both. Ah, but here is what makes SMF cool. They offer bridge systems that make it so that you can connect to a CMS system from SMF.