Another major plus for Markdown is its support now in Doxygen, since 1.8, which means when I write my pages describing software design I can do so in Markdown, getting instant previewing and export. It uses the extensions from PHP Markdown Extra, and GitHub flavored Markdown. I've found the simple tables and fenced code blocks incredibly useful. Full details at http://www.stack.nl/~dimitri/doxygen/markdown.html

@Liam Thanks for setting up the w3c page but it seems to present a few barriers to entry by more formal disclosure than most fora "* Employment Affiliation. You must indicate any significant employment relationship" I'm not even sure I'm allowed to put the company name on stuff I do on my own time pursuing my own interests!