I've also been using the UseMod wiki, and found it simple to manage and fast enough.

Although most of the time I'm using it with fairly savy computerists, I've also set up some discussion boards with UseMod wiki for some academic student/faculty committees. Some of the committee members didn't like the wiki, but I think those folks would have balked at anything online. Many of the people on the committes found it a useful tool.

I have looked at the Everything engine a bit, but so far the overhead in setting up a sql engine for it and mastering its customization world has been a bit too much.

If you want to look at UseMod, see http://www.usemod.com/cgi-bin/wiki.pl?UseModWiki/Download