Ruby on Rails 4.0 Release Notes — Ruby on Rails GuidesHighlights in Rails 4.0: Ruby 2.0 preferred; 1.9.3+ required Strong Parameters Turbolinks Russian Doll Caching These release notes cover only the major changes. To learn about various bug fixes and changes, please refer to the changelogs or check out the list of commits in the main Rails repository on GitHub. 1. Upgrading to Rails 4.0If you're upgrading an existing application, it's a great idea t
