Here's an article that shows how to set up both Rails 3.2 and 4.0 with Ruby 2.0. Uses some new features of rvm. "With both versions on your machine, you’ll expl

Here's an article that shows how to set up both Rails 3.2 and 4.0 with Ruby 2.0. Uses some new features of rvm. "With both versions on your machine, you’ll explore the new features of Rails 4.0 while continuing to develop projects with the most recent stable version." http://railsapps.github.com/installing-rails.html http://railsapps.github.com/installing-rails.html