CKEditor - Real-time collaborative future-ready rich text editor
Markdown by DaringFireball - Text-to-HTML conversion tool/syntax for web writers, by John Gruber
Aloha Editor - Aloha Editor is an HTML5 WYSIWYG Editor that gives you a total new experience when editing.
Asciidoctor - In the spirit of free software, everyone is encouraged to help improve this project.
ContentTools - A small & beautiful WYSIWYG editor for HTML content.
pandoc - Pandoc is a Haskell library for converting from one markup format to another, and a command-line...