Ruby on Rails/Getting Started/Install on Linux
Install on Linux 
Install or update Ruby 
It is important that you get the right version of the language. Versions 1.8.2 and 1.8.4 are recommended. 1.8.3 has problems, and 1.8.5 (the current stable version) runs fine, but you will not be able to use breakpointer for debugging (a very handy tool). So I recommend 1.8.4.
Get it from the offical Ruby website
Get it from the SVN repository
For Debian-based systems (Debian, Ubuntu, etc.), your best bet is to type:
sudo apt-get install ruby -t '1.8.4' sudo apt-get install irb rdoc
This should install the Ruby language interpreter, the RDoc documentation generator, and irb command-line interpreter.
Install RubyGems 
You should be able to obtain RubyGems by going to the Gems Website and clicking the "download" link. Choose the proper archive and install.
Install Rails 
Get to the command-line and type:
sudo gem install rails --include-dependencies