GeSHi Filter is based off of the codefilter module.  I added syntax highlighting 
and branched it off into a new module. All syntax highlighting features and the config
page have been added by me.
 - Vincent Filby <vfilby@gmail.com>

Credits for codefilter modules:

This mini-module was made by Steven Wittens <unconed@drupal.org>, based on the
PHP filter in Kjartan Mannes's <kjartan@drupal.org> project.module.

