We recommend Ruby 1.8.7 or Ruby 1.9.2for use with Rails. Ruby 1.8.6 and earlier are not supported, neither is version 1.9.1.
RubyGems is the standard Ruby package manager. It's similar to apt-get, emerge, and other OS package managers.
(extract, then run "ruby setup.rb")
With RubyGems loaded, you can install all of Rails and its dependencies through the command line:
gem install rails
New versions of Rails can be installed the same way. Rails can also be downloaded as stand-alone packages.
Make your application
Create your application skeleton and start the server:
rails new path/to/your/new/application
You're running Ruby on Rails! Follow the instructions on http://localhost:3000.
with lots of plugins
There's a world of extensions to the core Rails framework through plugins. They provide cool functionality that may not be needed by most of the people most of the time, but still serve a spot for those exceptions where you do need more. Read more about plugins at Agile Web Development.