CKEditor - Real-time collaborative future-ready rich text editor
Markdown by DaringFireball - Text-to-HTML conversion tool/syntax for web writers, by John Gruber
Summernote - Summernote is a JavaScript library that helps users create WYSIWYG editors online.
Textile - Textile is a lightweight markup language originally developed by Dean Allen and billed as a...
Froala Editor - Froala Editor is a WYSIWYG HTML editor that enables rich text editing capabilities for the applications.
Typora - A minimal Markdown reading & writing app.