There is a [Creole parser plugin|http://moinmoin.wikiwikiweb.de/ParserMarket/WikiCreole] for the [MoinMoin wiki engine|http://moinmoin.wikiwikiweb.de].

It is based on the [Creole0.4] draft.

There are several things not totally right:
* The expression for urls used is an approximation. In particular, commas, dots, exclamation marks and such are included in the url only when not followed by a space, so that you can write {{{http://news.com/article/2006,09,06}}} as a link, but also {{{see those two pages: http://one.org, http://two.org}}}. Other special characters are included in the url, but escaped when appropriate.
* no "smart" resolving of ambiguity between **bold** and lists
* {{{#pragmas}}} from the top of page are filtered out before the parser gets to them, so it's possible to have a numbered lists broken this way
* Pre blocks use hashbang notation for denoting code type (for syntax highlighting).
* The {{{<<placeholder>>}}} syntax is used for macros,
* The {{{{{image}} }}} syntax is used for attachments.
* There is an option for switching between wiki-like and blog-like lines.

I'm also thinking about writing a mixed-mode parser, but this can be pretty weird.