http://openwiki.com/ow.asp?OpenWikiInDotNet
Open Wiki In Dot Net

http://www.flexwiki.com/
FlexWiki

http://www.onlamp.com/pub/a/onlamp/2004/11/04/which_wiki.html
Which Open Source Wiki Works For You?

http://www.usemod.com/cgi-bin/wiki.pl
UseMod Wiki

http://www.usemod.com/cgi-bin/mb.pl
Meatball Wiki