ProseMirror – A toolkit for building rich-text editors on the web
ProseMirror is easily the best source code I've ever worked with. The components are so well architected, that inside the codebase there's a 100 page book on software design principles waiting to come out. I'm serious. Marijn Haverbeke should certainly write a AOSA (http://aosabook.org/en/index.html) style piece on how & why the software is architected in such way.What sets ProseMirror apart from the rest (Slate, Quill, Trix, Draft, etc.) is - ProseMirror isn't simply a library. It's an entire platform with all bits and pieces needed to build a simpler rich text library. Rightly named "toolkit" instead of a "library".Source: We are using it to build our soon-to-be-released rich text feature in comments for Zoho Writer (https://writer.zoho.com)