PhpWiki is a simple PHP based Wiki which supports flatfile, DBA and SQL backends (via PHP's PEAR stuff). You can find more information about PHPWiki here:
I'm also using this page to keep notes on things I'd like to see implemented (less grandious ideas then those on the DreamWiki page), or might even try and implement myself.
- A "Remove trailing whitespace ..." button on the edit page.
- A file upload feature (should attach files to a wiki page).