People rave about node.js and kock ruby. People rave about ember and knock backbone. But when it comes to building apps, the tried and true approaches are the best I've found. There is plenty of documentation online and that really helps when you are starting out.
When I gave ember a whirl, the lack of documentation, forums, or just anyone using it -- outside a core group -- was very disturbing.
I just gave Ember a whirl the other day because I wanted to fiddle around with a prototype for an experimental interface. I'd had a little exposure to Ember and related projects before, and generally liked it, but hadn't really set it up entirely from scratch.
It was... amazingly annoying. And I don't just mean the fact that I needed to search around for a box that had an appropriate version of Ruby installed to build the ember-data project from source (heaven forbid that they offer a download of JavaScript, let alone a single package of all the libraries you're going to want to use for your project -- but it's okay, I'll forgive you, you're a release candidate). I mean the stuff where I wanted to load a simple skeletal data structure in JavaScript from JSON with a FixtureAdapter before attaching it to a real backend, and the documentation was all "sure, you can totally use a non-REST store!" -- http://emberjs.com/guides/models/defining-a-store/ -- but wasn't really strong on the How. Fortunately, StackOverflow came to my rescue: http://stackoverflow.com/questions/15301918/how-do-you-set-t...
But it was a negative experience. If I hadn't been exposed to a taste of its power and elegance before, I would have probably given up.
When I gave ember a whirl, the lack of documentation, forums, or just anyone using it -- outside a core group -- was very disturbing.