Rails3-appGenerator-Devise is a project mainly written in Ruby, it's free.
Application Generator for Rails 3 App, with JavaScript Libraries Configurator, YUI, JQuery, RaphaelJS, Cufon, YUI Test Cases, etc
= JSlib Rails Application Template
Goal[http://jessecravens.com/01302011/JSlib-rails-application-template]
Generates a Rails app; includes necessary JS Libraries from Google's CDN, Haml, RSpec, Cucumber, WebRat, Factory Girl ...
== Generating an Application
In Rails 3, navigate to your projects directory, and create a custom templates directory if you don't already have one
mkdir tmpls
Clone the template.rb file to your custom templates directory
git clone git://github.com/jessecravens/jslib-rails-template.git path_to_templates
Generate a new app named JSlibapp, or whatever you like
rails new JSlibapp -m path_to_templates/template.rb
Navigate to the new directory
cd JSlibapp
Start your server
rails s