Wikis for documentation: great in theory, sucks in practice.

Make a change to source, then you have to figure out where the wiki page is for it. Can't find the wiki page? Make a new one. What folder does it go in? Do you make a new folder? What if a page does exist, but it's wrong? Do you fix the whole thing? Just the part you added? Email the person who last updated it?

After 6 months it ends up being a tangled mess of insanity, and no one relies on it. You complain about outdated/indescipherable comments? Imagine that multiplied out. In fact, it's almost worse; at least with code you can try to think like a compiler and figure it out. Without code--yikes!