1. make directory
# mkdir /opt/rails

2. Install ruby 1.8.7
# wget ftp://ftp.ruby-lang.org/pub/ruby/ruby-1.8.7-p22.tar.gz
# tar xvfz ruby-1.8.7-p22.tar.gz
# cd ruby-1.8.7-p22
# ./configure
# make
# make install

3. Install RubyGems
RubyGems is standard package management program of Ruby
# wget http://rubyforge.org/frs/downlad.php/60718/rubygems-1.3.5.tgz
# tar xvfz rubygems-1.3.5.tgz
# cd rubygems-1.3.5
# ruby setup.rb

4. Install rails
# gem update --system
# gem install rails --include-dependencies

5. Install mongrel
# gem update --system
# gem install mongrel --include-dependencies
# gem install mongrel_cluster --include-dependencies