Argon.js

Client-side MVC framework with Node.js backend (i.e. batteries included), written in CoffeeScript, for rapid web application development.

Features

Only ~500 lines of CoffeeScript source code
Minimized & gzipped size less than 5 KB
No dependencies (not even jQuery)
Fast DOM-based template engine
Client-server communication over websocket
Code shared between server & client (model validation etc)
Server-rendered pages for search bot support
MongoDB storage included

Note: this is unfinished technology preview version!