I think you talk about Cappuccino and Objective-J somewhere else on this site. I think it is the best answer fitting your desires so far. If you used Google App Engine as the back end, you would still need to write in Java or Python on the back end. But depending on your app you might not need to do that much on the back end. So not a lot of coding there - do some in python to fetch and serve data requests from your front end, and put all the biz logic in the front end, which would be Cappuccino and just about like coding in Cocoa.