As simple as possible backbone.js app to demonstrate how to wire one up. Does not even have a serverside, just persists full crud clientside with the server calls commented out. It lets you create, read, update, delete notes, all with hashtag urls via a Backbone.js router.
anything that supports REST endpoints and JSON format will work just fine. Even if the server-side you are working with does not support full REST, then you can just switch on the _method param that gets posted as an alternative. I personally have mostly use Backbone.js on top of a Rails stack.