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.
Textile - Textile is a lightweight markup language originally developed by Dean Allen and billed as a...
ContentTools - A small & beautiful WYSIWYG editor for HTML content.
Typora - A minimal Markdown reading & writing app.