Special thanks go out to Bob Glamm, Aaron Kalin, and Stephane Le Solliec for their very active efforts leading to this release. Thanks, guys. :-)
Text_Wiki is a PEAR package that abstracts parsing and rendering of wiki markup. It is object-oriented, so you can add, modify, or remove rules without having to edit the core code. It is used in YaWiki (a Yawp-based project) and the Horde Wicked project.