Knockout.js vs Backbone.js

I've been using Backbone at Earbits (YC w11) [1] since February and have been very happy with it. We're running a pretty complex AJAX app that streams music along with providing a large set of functionality around the music itself (artist info, local concert alerts, track history, deep facebook integration, bookmarking favorites, event logging, running contests and promotions and so on).

For an idea of scale, we have: ~60 backbone views, ~120 javascript templates (underscore jst), ~30 backbone models + collections, 1 controller (the router)

And we have a fairly complex system of white-labeling that allows us to swap out javascript templates and augment view functionality for partner sites [2] and local sites [3] without adding a lot of overhead.

The combination of Backbone + Underscore + Jammit with Rails/Rack on the backend is working great. Even developers who are not familiar at all with Backbone and the ajax app, can dive in and understand everything pretty quickly.

Can't possibly recommend it highly enough, if you 1) are comfortable with Javascript, and 2) prefer to roll most of your own code so that you're not beholden to bulky rigid frameworks.

There are some quirks that annoy me, but overall I can't complain. One of these days when I have some more free time, I'll try and write a series of posts explaining how we're using it and our key learnings.

[1] http://earbits.com [2] http://sfgate.earbits.com [3] http://la.earbits.com

The real competition to Backbone in this space in my mind is Sproutcore 2. At its core it's lightweight enough to be a drop-in replacement but has a vastly more sophisticated approach to handling dom updates, cascades of updates, data bindings and dealing with large sets of data.

Every time I would try to learn and like Knockout.js, I was always put-off and immediately stopped from disgust after seeing all the data-bind attributes all over the place, destroying the separation between presentation and business logic.

But, after reading some of those answers, I'm very happy to see that you can now work with a fork of "unobtrusive" knockout. I'll definitely have to give it another chance.

I would recommend looking at Spine as well:

http://maccman.github.com/spine/

It's smaller than Backbone and IMHO also makes you write cleaner code. It has real controllers as well. Backbone has routes instead which works for a data-driven page-based application (say a CMS or something) but doesn't work that well for more GUI-like stuff (like a media player).

Unfortunately it doesn't have a big community and many users like Backbone.

I'm happily using Backbone.js on several projects on the client side, including with VIE: https://github.com/bergie/VIE

One of the cool things is that Backbone models and views can be quite easily used also on the server-side with Node.js. In some applications both sides use the same models, with Backbone.sync being the difference - on client you communicate with AJAX, on server you communicate with a custom database connector.

I wish someone would write a very simple databinding helper to let backbone do some of that ultra easy UI databinding too.

So far, I've seen every Knockout feature implemented directly or indirectly (via plugins) in Backbone.js

Thank you for posting this link. I'm in the process of choosing between the two. So far knockout.js is winning.

Why is the ordering of answers so messed up on this particular stackoverflow question?

I think Batman.js(by the Shopify guys) would be a good competitor in the space too.