Rails just keeps on changing. Both Rails 3 and 4 as well as Ruby 1.9 and 2.0 bring hundreds of improvements including new APIs and substantial performance enhancements. The fourth edition of this awardwinning classic has been reorganized and refocused so its more useful than ever before for developers new to Ruby and Rails. Rails 4 introduces a number of userfacing changes and the book has been updated to match all the latest changes and new best practices in Rails. This includes full support for Ruby 2.0 controller concerns Russian Doll caching strong parameters Turbolinks new test and bin directory layouts and much more. Ruby on Rails helps you produce highquality beautifullooking web applications quickly. You concentrate on creating the application and Rails takes care of the details. Tens of thousands of developers have used this awardwinning book to learn Rails. Its a broad farreaching tutorial and reference thats recommended by the Rails core team. If youre new to Rails youll get stepbystep guidance. If youre an experienced developer this book will give you the comprehensive insider information you need. Rails has evolved over the years and this book has evolved along with it. We still start with a stepbystep walkthrough of building a real application and indepth chapters look at the builtin Rails features. This edition now gives new Ruby and Rails users more information on the Ruby language and takes more time to explain key concepts throughout. Best practices on how to apply Rails continue to change and this edition keeps up. Examples use Concerns Russian Doll caching and Turbolinks and the book focuses throughout on the right way to use Rails. Additionally this edition now works on Ruby 2.0 a new release of Ruby with substantial functional and performance improvements. This edition is for Rails4.0 and beyond.