Text::WikiCreole is a Creole 1.0 parser written in Perl.  It features:

* One-pass parsing.  Call it a regex/statemachine hybrid.
* Complete 1.0 implementation, plus...
** Plugins
** Definition lists
** Indented Paragraphs
** Monospace, superscript, subscript, underline
** Trademark, Registered Trademark, Copyright, ellipsis, and dash special characters
* Custom link altering function (prefix base URL, port, etc)
* Tag customization for CSS, etc

It's grammar based, so could be easily adapted to parsing other dialects or (more easily) for converting Creole to other dialects.

[[http://search.cpan.org/~jburnett/Text-WikiCreole/|check it out]]