Get Ruby on Rails in no time

Rails is low on dependencies and prides itself on shipping with
most everything you need in the box. To get started, just install
Ruby, the language, and RubyGems, the package manager.

Ruby

Ruby We recommend Ruby 2.2 or newer for use with Rails. Rails requires Ruby 1.9.3 or newer.

Source: Compile it yourself
Windows installer: Ruby, popular extensions, editor
OS X 10.5+: Included with developer tools
(then do gem update rails)

We recommend managing your Ruby installation through rbenv. It’s an easy way to run multiple versions for different applications and update when a new release is made.

Rails

With Ruby installed, you can install all of Rails and its dependencies through RubyGems on the command line:

gem install rails

New versions of Rails can be installed the same way.

Make your application

Create your application skeleton and start the server:

rails new path/to/your/new/application
cd path/to/your/new/application
rails server

You’re running Ruby on Rails! Follow the instructions on http://localhost:3000.

Editors

TextMate on OS X has long been the favored Rails editor, but the classic editors are still going strong. See VIM for Rails and Emacs for Rails. For a full-on IDE, check out JetBrains RubyMine.