Due to being on a Unix server and not wanting to try and install MySQL or deal with PHP, I found a free forum download, YaBB, that is easy to install and add new features to. The site is
http://www.yabbforum.com.
There are two forums that are run at the site. The first is for the full forum download and other miscellaneous stuff. The second one (which is where I seem to live now) is for modifications (Mods) to the forums. Everyone at these sites are very friendly provided you have tried everything to find the answer in the boards previously. (Otherwise, they'll get a bit snippy, but nothing too harsh.)
If you want to see the boards in action, check out mine at
http://www.csun.edu/~robodox/YaBB/cgi-bin/yabb/YaBB.cgi. You'll have to register to view the general categories.
Any questions, email me at
robodox@csun.edu.
indieFan