Slate : Slate is a completely customizable framework for building rich text editors.
Slate lets you build rich, intuitive editors like those in Medium, Dropbo...
RequireJS : RequireJS is a JavaScript file and module loader. It is optimized for in-browser use, but it can be used in other JavaScript environments, like Rhino ...
Bliss.js : Want to use Vanilla JS but find native APIs a bit unwieldy? Bliss is for you
Styletron : Styletron is a universal CSS-in-JS engine built from the ground up for high-performance.