Ruby plugin for Eclipse

I found a Ruby plugin for Eclipse at: http://update.aptana.com/update/rails/3.2/

I had first to install Eclipse Monkey, described at http://www.brain-bakery.com/projects/articles/eclipse-monkey-scripting/. Also I had to install the Aptana Studio from: http://www.aptana.com/docs/index.php/Plugging_Aptana_into_an_existing_Eclipse_configuration

There are some instructions on how to use at: http://www.ibm.com/developerworks/opensource/library/os-rubyeclipse/