CKEditor - Real-time collaborative future-ready rich text editor
JavaScript - Lightweight, interpreted, object-oriented language with first-class functions
Aloha Editor - Aloha Editor is an HTML5 WYSIWYG Editor that gives you a total new experience when editing.
AlloyEditor - Modern WYSIWYG editor built with a sleek React UI on top of CKEditor
Qt - Powerful, flexible and easy to use, Qt will help you not only meet your tight deadline, but also reduce the maintainable code by an astonishing percentage.
Trumbowyg - Feature-packed WYSIWYG editor in only 15kB of JavaScript