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 [Creole0.1] draft.

There were several issues when writing it:
* The line breaks are a major pain. Currently I only add them inside paragraphs, and I included a special case that will not add a line break at the end of a paragraph if it is followed by an empty line. The line break is however added if the paragraph is followed by a list or a preformatted block, and I personally don't feel like adding more lookahead special cases.
* 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.
* I'm a little bit generous when parsing mixed lists. This is valid:

{{{
# One
- Two
- Three
# Four
}}}

and gets rendered as:

# One
# Two
# Three
# Four

How should be such and similar errors handled?

----

I would say that should be rendered as:

# One
* Two
* Three
# Four

--[ChuckSmith]

That was the previous result, but it could be abused to get two-level lists by users. The current one is just a kind of trying to fit it, without giving the users additional functionality (which they would instantly abuse, making the pages incompatible with other creole wikis). In the end I will just introduce and additional class for 'error', and will render all such things as 'errors', which then can be rendered with css into something really ugly ;). -- [RadomirDopieralski], 2006-09-06

I know you're joking, but one of the main principles of wikis is that they can render things "wrong", but never as an error.  Users will simply see that what they typed didn't come out they way they wanted and try again.  --[ChuckSmith], 2006-09-06

I'm not joking. If every combination is supposed to be rendered **somehow**, then WikiCreole has a much harder task than anticipated.
-- [RadomirDopieralski], 2006-09-06

Ok, I returned to the previous behavior, as suggested here. Now I'm working on making the list starting with more than 1st-level item somewhat sane. The change forth and back made my code shorter for about 20 lines, so I'm happy anyways ;).
-- [RadomirDopieralski], 2006-09-06