Double Shot #1609

Rails 5.0.0.beta1: Action Cable, API mode, Rails command - New version is thundering at us, bearing new dependencies. There's also a video walkthrough to bring you up to speed on Action Cable.
A Guide for Upgrading Ruby on Rails - Now covers the 4.2 to 5.0 beta transition.
You Don't Need jQuery - How to use native DOM manipulation instead. Of course you give up some things like compatibility with older browsers and succinctness.