Markdown by DaringFireball - Text-to-HTML conversion tool/syntax for web writers, by John Gruber
GitHub Flavored Markdown - GitHub uses "GitHub Flavored Markdown," or GFM, across the site--in issues, comments, and...
Minimalist Markdown Editor - This is the simplest and slickest Markdown editor.
Textile - Textile is a lightweight markup language originally developed by Dean Allen and billed as a...
Typora - A minimal Markdown reading & writing app.
StackEdit - Full-featured, open-source Markdown editor based on PageDown, the Markdown library used by Stack Overflow and the other Stack Exchange sites.