I'm the author of backbone-rails, one of the main differences that I see is I provide a Backbone.sync method that plays nicely with rails conventions of namespacing your put/post params by model name. It also adds csrf-token to the header in the request for you.

However, I think both of our projects are mainly just about helping users learn how to use backbone.js with rails. I try to balance the pull requests I accept based on usefulness vs will this actually help or confuse a new user trying to get started with rails and backbone. Use either one that makes more sense to you, as long as we helped some users get started with backbone and rails then I think we did our job.

My main focus was to follow the thoughtbot naming conventions and keep it simple.

The specific differences are: different naming conventions, fewer generators, generates Coffee or JS.

I wrote a short comparison here: https://github.com/meleyal/backbone-on-rails/wiki/How-is-thi...

I published my notes on the differences as a blog post, "backbone-on-rails vs backbone-rails vs rails-backbone". http://www.coffeescriptlove.com/2011/11/backbone-on-rails-vs...

I think backbone-rails comes with the older 0.5.0 version of backbone.js, whereas this one has 0.5.3 version. But i haven't tried it so not sure of other differences.

This one says it supports coffeescript or javascript scaffolding(backbone-rails only supports coffeescript scaffolding right now)

not sure, but if anyone has a good comparison I'm interested.