Sometimes people ask me what wiki software to use. The short answer is "I don't know." But I can't say that. So usually, I ask these three questions:
- Are you willing to pay for it?
- Do you want to host it yourself?
- Do you want to hack it?
Generally, with that information I can point them at one of the handful of wiki packages I know about. If you're willing to pay, you're usually in a different class than people who want to hack it. I personally use Kwiki, for example, because I can hack it and because other people hack it, I don't mind hosting it myself, and I'm not willing to pay. For people who want a professional, hosted tool, I usually recommend SocialText.
Today, I found a tool that might help me answer that question for people a little more comprehensively. WikiMatrix lists 21 wiki packages. Click the radio buttons next to the one's you're interested in and press the button, you'll get a click comparison matrix that compares the tools on dozens of feature points. No coverage of commercial (or maybe it's hosted?) wiki packages that I can see (JotSpot and SocialText aren't there, for example). Even so, this is very useful and I'll be pointing people at it.