All three frameworks are excellent at helping us build ambitious front-end applications; you simply can't go _wrong_ by picking one over the other. If a particu

All three frameworks are excellent at helping us build ambitious front-end applications; you simply can't go _wrong_ by picking one over the other. If a particular framework's trade-offs don't for any part of the app (performance for example), you can always write just that part in a different way (manual DOM manipulation). But to contrast all three, I'll pick the area I'm most interested in - templating. The purpose of a framework is to render a dynamic view without the programmer having to wire up every state transition with a corresponding view transition. This is done by templating content with state, mediated by the framework. And how this is done affects the entire design of the framework and apps written on them. Angular and Ember allows state and logic inside HTML. They figure out which state variables and corresponding templates go together and re-renders them automatically. The pro is that writing a modified version of HTML without too much code lets us have a dynamic app running in no time. The con is that there is a new language to study - with its own parser, control structures, scoping, and quirks. React on the other hand lets us specify templates as Javascript functions which are run whenever the state changes. The pro is that there is no new language abstraction to learn; it re-uses Javascript. External DSLs especially are in an uncanny valley - they're not full-blown languages but have enough quirks to be bothersome. Language abstractions forces a virtual machine (the language parser/interpreter) to evaluate the code, and it is an opaquely magical layer that makes it hard to see the entire stack of abstractions during day-to-day programming. It also forces a separation between our view (written in the templating language) with the rest of our code. The con of this approach is simply more code to write; the programmer has to anticipate and inform the framework of any state changes. With setState this isn't as bad a trade-off as we'd imagine. And MobX meanwhile brings an Angular like state abstraction to React - it watches over observables and automatically fires re-render. The other big difference is that React is not opinionated. It is a very much a framework alright, but it for example doesn't ship with a router, nor does it prescribe a framework for organizing the code. Ember has so far done a great job here - I often wish I could combine the Ember ethos of backwards compatibility, great documentation, and a fanatic love for the existing users of the framework, with the way React approaches templating and composing components. I haven't had the chance to look at Angular 2, but for me, Angular 1 started the front-end revolution happen, and I'm curious what they have done this time.