Install the latest stable Ruby and Rails on Ubuntu 9.04

Install the prerequisite packages using the following command.

$ sudo apt-get install build-essential libssl-dev libreadline5-dev zlib1g-dev

Install Ruby
Download the latest version of ruby

$ wget ftp://ftp.ruby-lang.org/pub/ruby/stable-snapshot.tar.gz

Untar the package

$ tar xzf stable-snapshot.tar.gz

Compile and install

$ cd ruby/
$ ./configure
$ make
$ sudo make install

Create a symbolic link to ruby

$ sudo ln -s /usr/local/bin/ruby /usr/bin/ruby

Install RubyGems

$ wget http://rubyforge.org/frs/download.php/56227/rubygems-1.3.3.tgz

Compile and install

$ tar xzvf rubygems-1.3.2.tgz
$ cd rubygems-1.3.2
$ sudo ruby setup.rb

Install Rails

$ sudo gem install rails