PhpMyFAQ

Quoting the Freshmeat.net page:

phpMyFAQ is a multilingual, completely database-driven FAQ system. It support various database systems and it also offers a content management system with a WYSIWYG editor, an image manager, flexible multi-user support, a news system, user tracking, language modules, templates, extensive XML support, PDF support, DocBook XML support, a backup system, and an easy to use installation script.

Links

 * phpMyFAQ's Homepage
 * Freshmeat Record