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).
Thus, "Markdown" is two things: (1) a plain text formatting syntax; and (2) a software tool, written in Perl, that converts the plain text formatting to HTML.
Implementations:
- Make.text - a bookmarklet for translating a web page into Markdown.
- PyMarkdown - for Python, obviously.
- python-markdown2 a second Python implementation, with some improvements.
- BlueCloth for Ruby
- PHP implementation
- C#/.NET implementation
- JavaScript partial implementation, a better one called "Showdown".
- A more complete list maintained by François Granger, who is developing a markup converter.