Cloverleaf is a framework for you to enable Node.js and CoffeeScript in your Cocoa application. Examine TestApp for an example application.
This is a work in progress, but progress is good. Scripts have access to the full Cocoa API and can instantiate classes and call methods. Before we can get serious, however, we need to be able to have Cocoa call back into our scripts, and that's coming soon.
Please throw me questions or comments here or on freenode.net, where I can be found in #Node.js and #coffeescript.