While I fully endorse emscripten ( see
http://web3dblog.wordpress.com/2012/11/19/news-on-bananabrea... ) I started to play around with
https://github.com/rogerwang/node-webkit which is a precompiled chromium that loads a HTML/CSS/JS-Zip file - no compilation at all. If you are in the WebGL/Three.JS field this might be another way to go. I will follow both paths.