http://railsgeek.com/2009/5/6/installing-the-ruby-enterprise-edition-regardless-of-the-preinstalled-ruby

Honestly, no secret that RubyEE much more productive than standard Ruby. Many use it in conjunction with a passenger, that allows to achieve excellent results in the speed of the application, and in doing so to save memory. I'm going to tell about experience of myself. I have a vps with 360 megabytes of RAM, so launching more than 6 projects becomes difficult using mongrel or thin, as these processes are continuously running in memory, regardless of whether the load on the application or not. After I installed mod_rails, I noticed an interesting feature - if anyone application is not used, the process of unloaded from memory, respectively, releasing more memory for other projects loaded. It was a pleasant surprise for me. In the other hand, ruby 1.8.6 (2008-08-11 patchlevel 287) is more preferable than ruby 1.8.7 (2008-08-11 patchlevel 72) and other.

So, let's go to install rubyee mod_rails. I want to give a small warning about the system's interpreter of ruby - no need to remove or recomiple from an older version (older repo), because your operating system has a hard dependency within allover packages, and the repository contains the required version of ruby. No need to touch system Ruby.

Let's start with the installation rubyee http://www.rubyenterpriseedition.com/download.html

You need to install some developers packages in Ubuntu case: sudo apt-get install libssl-dev sudo apt-get install libreadline5-dev

tar xzvf ruby-enterprise-X.X.X.tar.gz ./ruby-enterprise-X.X.X/installer

Ok, you have installed version RubyEE in the directory /opt/ruby-enterprise-1.8.6-20090421/bin/ruby Make symbolic links

sudo ln-s /opt/ruby-enterprise-1.8.6-20090421 /opt/ruby_ee sudo ln -s /opt/ruby_ee/bin/erb /usr/bin/erb_ee sudo ln -s /opt/ruby_ee/bin/gem /usr/bin/gem_ee sudo ln -s /opt/ruby_ee/bin/irb /usr/bin/irb_ee sudo ln -s /opt/ruby_ee/bin/rails /usr/bin/rails_ee sudo ln -s /opt/ruby_ee/bin/rake /usr/bin/rake_ee sudo ln -s /opt/ruby_ee/bin/rdoc /usr/bin/rdoc_ee sudo ln -s /opt/ruby_ee/bin/ri /usr/bin/ri_ee sudo ln -s /opt/ruby_ee/bin/ruby /usr/bin/ruby_ee

Done! Now you have an independent Ruby interpreter, as well as the independent "gem", with its own set of plugins Try to check

ruby -v ruby_ee -v gem list gem_ee list

ruby script/server ruby_ee script/server

Have a joy with Ruby Enterprise Edition!