Phoenix is a framework written in Elixir. It's creator, Chris McCord, showcased an impressive new feature called LiveView at ElixirConf.

LiveView is an extension of standard Phoenix views that will automatically propagate updates to the browser anytime state changes that would impact that view (using the existing Phoenix channels infrastructure). Instead of sending a state change event down the wire that you have to process in JavaScript manually, LiveView sends down an updated HTML fragment, diffs it against the current DOM state, and makes the necessary mutations for you.

Here is some more background info on LiveView: