Here's a previous discussion on Quill https://news.ycombinator.com/item?id=7716376 and a recent discussion on Trix, another rich text editor: https://news.ycombinator.com/item?id=10410879
The most comprehensive/updated list of editors I know of is here: https://github.com/cheeaun/mooeditable/wiki/Javascript-WYSIW...
(It doesn't do much to compare/evaluate the options, but it's pretty up-to-date/comprehensive, which is a start)