I've updated my Markdown Plugin for b2evolution to v0.2. It is now compatible with the 1.10.x series of b2evolution.
In case you're not familiar with it, b2evo is a wonderful little GPL'd blogging tool that packs quite a punch under its hood. It's undergone a ton of new changes since the stable 0.9.x series, and upgrading to the new version was a snap.
This plugin uses Michel Fortin's PHP Markdown so that b2evo bloggers can write their posts in John Gruber's Markdown syntax. In the words of Gruber:
Markdown is a text-to-HTML conversion tool for web writers. Markdown allows you to write using an easy-to-read, easy-to-write plain text format, then convert it to structurally valid XHTML (or HTML).
A Technical Note: I'm distributing PHP Markdown 1.0.1h with a small modification; lines 726-736 are uncommented such that Markdown shortcut links, a non-standard feature, are implemented (check out the "Markdown Plugin Usage" section of the README.html file for more).