The asset pipeline which was introduced in Rails 3.1, has been extracted to a separate gem called sprockets-rails. Performance for assets compiling has been improved. There is a open pull request to merge turbo-sprockets-rails3 to sprockets-rails, which would improve its performance further more.
Easily map modal validation to client side javascript in Rails. Github: https://t.co/ucqUcsuO Railscast: http://t.co/Og6vWbGy #rails
— Akhil Bansal (@bansalakhil) October 12, 2012
With the commit c82cf81f00f
Action and Page caching has been extracted from Action Dispatch as `actionpack-action_caching` and `actionpack-page_caching` gems