On the other end of the spectrum, I would be happy if I could install a wiki and share the login credentials between WordPress and the wiki. I hacked MediaWiki a while ago to share logins with anot...
WPMW is an extension for integrating a MediaWiki within a WordPress installation. It is currently working and useful, but beta-quality. (Not working since MW 1.27)
MediaWiki should not need any introduction to those of you who have been making Wikis online for a while now. There is no doubt that MediaWiki is a quite capable content management system for Wiki sites. It is not that hard to learn your way around it either. But integrating it with your WordPress site …