AbiWord - AbiWord is a free software word processor.
Markdown by DaringFireball - Text-to-HTML conversion tool/syntax for web writers, by John Gruber
LibreOffice - Writer - Open-source cross-platform word processor.
GitHub Flavored Markdown - GitHub uses "GitHub Flavored Markdown," or GFM, across the site--in issues, comments, and...
Zoho Writer - Create. Review. Distribute
Texy! - Texy! is a lightweight markup language as well as converter of this format to XHTML, in a form of a...