nibjs

https://github.com/blambeau/nib.js

nib.js is a NibJS javascript library allowing to maintain javascript projects ala 'node.js' (modules, exports, require) while also targetting a web browser as execution platform. It contains a simple packager command (nibjs) that will convert your sources to a single and minified .js file to be embedded in the browser. Node.js's exports and require are correctly bounded.