I am using Node.js and Sproutcore.
My goal is to use same frameworks/libraries as much as possible on both sides so I don't have to learn two things to accomplish one thing.
Do you know libraries/frameworks that work on both ends (testing, http requests, javascript extensions etc)
"so I don't have to learn two things to accomplish one thing" You will need to learn both. I think maybe YUI is something you should look into. YUI will help you build your logic/business for both client and server.
http://developer.yahoo.com/yui/