From Darin Firewall
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
Incredible I have just discovered it, thanks to Movable Type, that comes with it as one of its html parser.
What I have discovered about it, is that there is also a python-based program I can install on my Arch Linux.
Why do it?, well because sometimes I want to write a draft, or even a final copy of a post for the blog. With Markdown is really easy to format the file, I can now use vim, to format write the post.
Then I can copy and paste it directly into Movable Type and use the Markdown editor to convert it to html, also in Drupal there is a module to parse Markdown, and its Markdown for Drupal.
But if you do not want to use that module, you can parse the file in Linux and then post the html file of the output, using the input format of full html of Drupal, or the same for Movable type, sure Word Press has something like that too.