Install Ruby
Windows
Using One-Click Ruby Installer is the easiest way.
Linux
I believe you can do it by yourself.
Install Star Ruby
Windows
Download Star Ruby binary from Downloads
Run install.rb and install Star Ruby.
..>ruby install.rbLinux
Get source code with Subversion. Please refer Google Code.
Exexcute commands showe below. Then finish compilation and instllation.
$ ruby extconf.rb
$ make
$ make install # or sudo make install