> dependencies on specific implementations are not required to build a framework that offers features I think this is incorrect. You can't offer features witho

> dependencies on specific implementations are not required to build a framework that offers features I think this is incorrect. You can't offer features without implementations; The feature will never be completely agnostic of its implementation. When you get a really strong shift in the possible implementations (for example: websockets or even long polling, vs rpc) then the feature (for example: dynamic UI), if re-implemented, starts exposing very different semantics and secondary features. To sum it up: if you implement a thousand ORMs based on SQL db's then they're all going to look the same, implement one thing based on a NoSQL database and you suddenly see how the "feature" of "storing data" suddenly becomes something different from what could be anticipated by the people who designed the original "feature" back in the SQL era. Let's not lie to ourselves and pretend that features are some wondrous thing poised in thin air above their implementations.