Hello,

In Ruby world, Eclipse is strongly associated with RDT for past years, 
however RDT is not only one Eclipse-based IDE out there.

Eclipse DLTK team released Milestone 6 of Ruby IDE 1.0 with extremely 
powerful code complete, navigation and search features. If you did not 
heard about the DLTK project before, please look at DLTK Ruby screencast 
from EclipseCon 2007 
(http://us.xored.com/~haiodo/EclipseCon07/dltk-ruby.mov).

Eclipse DLTK website: http://www.eclipse.org/dltk
More Information at: http://www.eclipsedltk.org
Installation and quick-start instructions: 
http://www.eclipsezone.com/eclipse/forums/t92525.rhtml

Kind Regards,
Andrey Platov