I'm in the stage of changing big parts of my current website (>10000 pages) completely wiki-based.
I like Meatball. I also like perl, nevertheless I chose PhpWiki, not mod_perl. Both are fast, perl wiki's have more features, but php is so much simplier. My movie database in php4 needed three days from learning the language to going public. Besides that, mod_perl randomly crashes at DBI calls together with the probably unsafely written mod_php4.
My favorite Wikis are PPR (of course), Meatball for the content, PhpWiki for the community and Sqeak for the features and UI.
Hey, welcome to MeatballWiki. Thanks for the compliments. By the way, another good PHP wiki is AndStuffWiki. -- SunirShah
Reini, I'd seen your name before here, welcome. -- MattisManzel