How to install and run Ruby on Rails applications on Debian Sarge. Install Rails 1. Install ruby First, you'll need Ruby. apt-get install irb1.8 libreadline-ruby1.8 libruby libruby1.8 rdoc1.8 \ ruby ruby1.8 ruby1.8-dev 2. Install gems Gems is a package manager. It is to Ruby what CPAN is to Perl or PEAR is to PHP. You will use it a lot to install Ruby extensions - or in this case, install Rails wi