MediumEditor - MediumEditor is a simple inline editor toolbar built with JavaScript.
CKEditor - Real-time collaborative future-ready rich text editor
Trix - A rich text editor for everyday writing.
Edtr.io - Intuitive WYSIWYG web editor, open source & fully adaptable.
Froala Editor - Froala Editor is a WYSIWYG HTML editor that enables rich text editing capabilities for the applications.
Summernote - Summernote is a JavaScript library that helps users create WYSIWYG editors online.