Quill is a free, open source WYSIWYG editor built for the modern web. With its modular architecture and expressive API, it is completely customizable to fit any need.

https://quilljs.com/

Personal thoughts:

A lot of potential will come out of this library and its being supported by a lot of companies.

However for me it misses one important feature (tables) therefore I left the code super simple and left it there :) feel free to pickup and improve.