darrinb

Easily include raw markup languages (HTML, CSS, PHP, etc.) in posts using custom quicktags. No need to encode, the filter does it 
for you. Creates convenient “encode” buttons for post authors in the HTML editor.

WP Post Encode

mitcho (Michael Yoshitaka Erlewine)

<a href="http://daringfireball.net/projects/markdown/syntax" rel="nofollow ugc">Markdown syntax</a> allows you to write using an easy-to-read, easy-to-write plain text format.
Markdown for WordPress and bbPress (Markdown-WPBB) is based on the famed PHP Markdown Extra by <a href="http://www.michelf.com/projects/php-markdown/" rel="nofollow ugc">Michel Fortin</a>, in turn based on the original Perl version by <a href="http://www.daringfireball.net/" rel="nofollow ugc">John Gruber</a>. All I did was make the same package work with bbPress too. ^^

Markdown for WordPress and bbPress

A text-to-HTML conversion tool for web writers

WP Post Encode vs Markdown for WordPress and bbPress