MULTiO is a project mainly written in JavaScript, it's free.
(defunct -- see latest Socket.io version!) Client/Server wrapper for Socket.IO aiming to minimize typical boilerplate code.
A wrapper that aims to simplify client- and server-side JS that utilize Socket.IO. See ./idea.js to get an idea of what server-side code might look like. See the 'uchat' project for a more comprehensive (albeit messy) example.