Markdown is intended to be as easy-to-read and easy-to-write as is feasible.
Readability, however, is emphasized above all else. A Markdown-formatted document should be publishable as-is, as plain text, without looking like it’s been marked up with tags or formatting instructions.
Markdown Extra1 is a special version of PHP Markdown implementing some features currently not available with the plain Markdown syntax.
The editor is based on the very lighweight markItUp2 editor.
Download, install and enable the Yoonique Markdown editor plugin.