Backbone.js 1.0.0 Underscore.js 1.5.0

Add the following to your Gemfile:

gem "backbonejs-rails", "~> 1.0.1"

Then use Bundler to install:

$ bundle install

$ rails g backbonejs:install

Optionally you can add -ich to the end of that command to have icanhaz.js included.

backbonejs-rails adds the necessary libraries to your Rails app for using Backbone.js.

• backbone.js
• underscore.js
• json2.js

For templates you can optionally include ICanHaz.js

$ rails g backbonejs:install -ich 

You can find my screencast on Backbone.js and Rails 3 here