I don't think it should be tied to a specific one, but it should have an api/adapter. Rails 3 is a good example of how I think it should be done. One advantage

I don't think it should be tied to a specific one, but it should have an api/adapter. Rails 3 is a good example of how I think it should be done. One advantage, I get form helpers that automatically know how to deal with models, display errors, etc.