Something else from LifeClever: the wiki matrix.
Since I started one of the more visible wikis on campus (well, I think it is anyway; certainly I've received queries from off-campus due to my name being attached to it) I also occasionally get questions from other staff members regarding what wiki is best. I chose twiki because at the time, the only other wiki on campus I knew of also ran that, and it was an easy install from the FreeBSD ports tree. I've since given up trying to maintain it using that - in fact, our twiki moved off a BSD box managed by me onto www.cs.uwaterloo.ca, a Solaris box mostly managed by a couple of other people in my working group. However, I don't feel at all pretentious when I say that I feel that the presence of a wiki in the Math Faculty will be one of my legacies.
I just wish I'd known about this site when I was considering different technologies.