In-browser code editing made bearable....

For a plethora of languages (more than just those i tagged it with) also offers vim keybindings

a Github style theme for use in Mou editor

The program uses standard streams to read from stdin() and write to stout(), so the script can easily be adapted to a wide-range of Markdown work flows. I typically use formd in one of three ways:

A Markdown formatting tool — Read more
converts between inline links and referenced links

Want a quick and beautiful Markdown cheat sheet. Own Marked.app?

live preview of markdown while you type. Similar to Emdee

Type in WYSIWYM and it generates markdown.... :) Perfect for people who don't want to type Markdown but could benefit from using it.

Texts is a new kind of editor for creation of text structure and content. Books, articles and blog posts written once in Texts can be processed and published in many formats.

think of it as a trivial way to leave a a note for others online

GuideKit will help you create better documentation with less effort, whether you’re building API documentation, first-time user guides, or in-depth tutorials. Getting started is quick and easy.

A Markdown parser for javascript

Instantly beautify your Github repositories' README.md with DocumentUp. Parses your github project's README into a good looking html page with nav.

A nice markdown parser for ruby with native extensions to make it run fast.

A simple online tool that converts static Markdown text files
located in your Dropbox, into a beautiful web log.

Write your tests in Markdown like a README, then execute them

Babelmark is a testbed for side-by-side comparisons of the output of various Markdown implementations.

JavaScript port of Markdown

Maruku implements the original Markdown syntax and all the
improvements in PHP Markdown Extra. Moreover, it implements some ideas
from MultiMarkdown, and adds a syntax for specifying metadata for
block elements.

Unlike Bluecloth, Maruku creates an in-memory representation of the
document tree, and this makes it very easy to export to other formats.

email client with built in markdown support

useful markdown list keybinding and a system service to clean up and renumber markdown lists in selected text

a syntax highlighter for the Markdown language, designed to be integrated into GUI text editor programs

creates sidebar outline from headers & supports different header sizes for different header sizes * IF YOU APPLY A CUSTOM THEME *

enables different header sizes for different headers

WordPress to Markdown ruby script. Parses existing WP categories into discreet list of categories. Also identifies link-style postings and sets a YAML attribute to identify those entries. Finally forces all content to be UTF-8.

can convert markdown & textile2 to xhtml, latex (and thus pdf),markdown, and textile2

Gimli is a utility for converting markup to pdf files. Useful for reports and such things.
It’s a developed version of textile2pdf to support multiple markup styles and to get syntax highlighting.

It’s inspired by the markup convertion in gollum. The markup code is adapted from gollum.
It works by converting the markup to pdf using PDFKit
The markup is converted to html using github/markup

stylesheet to allow for Byword styled preview in Marked.app

displays formatted markdown. Minimalist UI doesn't support full markdown (no images)

perl script that converts a MultiMarkdown plain text file into an OPML file that maintains the overall structure. It moves the metadata (if present) to the end of the file

online markdown editor & previewer

uses default keyboard so accessing special keys like square brackets is less than optimal. see Edito, which will also let you e-mail the markdown you've created.

distraction-free writing app that supports markdown

an extension to markdown syntax that'll allow you to convert to latex, html, and more.

plugin to enable markdown preview in Gedit

like the buttons you get when editing mediawiki only it's for markdown format. Supports live preview so it is WYSIWYG(ish) its rendering is build on the showdown javascript library. But WMD IS NOT OPENSOURCE

Pandoc is a Haskell library for converting from one markup format to another, and a command-line tool that uses this library. It can read markdown and (subsets of) reStructuredText, HTML, and LaTeX, and it can write markdown, reStructuredText, HTML, LaTeX

converts to XHTML, Latex, Markdown (standard), and s5 (dev version only)

extends Markdown syntax to work with complete documents that could ultimately be converted from text into other formats, including complete XHTML documents, LaTeX, PDF, RTF, or even (shudder) Microsoft Word documents.