ProseMirror
This is a well-behaved what-you-see-is-what-you-mean editor based on contentEditable, with support for collaborative editing and customizable document models.
The project page, which has a number of demos, is prosemirror.net.
NOTE: This project is in BETA stage. It isn't well-tested yet, there are no NPM modules yet, and the APIs may change at will for the time being. You are welcome to use it, but you can't expect it to be stable or mature yet.
This code is released under an MIT-style license. There's a forum for general discussion and support requests, and the Github bug tracker is the place to report issues.
Documentation can be found on the website.
Structure
This software is written as a collection of ES6 modules. Since JS
engines don't really run ES6 yet, it has to be compiled to ES5 to
actually run. You can use npm run dist to compile a copy of the
source tree under the dist directory. You would then typically use
Browserify,
Webpack, or something similar to package
up the modules you need for the browser.
Here's a rough overview of the source directories:
src/
model/ The document model
transform/ Operations on the document model
edit/ The editor
collab/ Collaborative editing module
inputrules/ Magic input (-- → —) module
convert/ Document conversion code to and from DOM, HTML, and Markdown
menu/ Menu UI modules
Most of these contain an index.js file that exposes the module's
content as a flat object (i.e. no attempts are made to make the 'main'
thing in a module the exported value or default export).
Run the demo
Install Node.js.
Inside the project directory, install the project's node dependencies
npm installBuild the demo, which will recompile files on change
npm run demoOpen demo/index.html in your browser