Rinari Is Not A Ruby IDE.
Well, ok it kind of is. Rinari is an Emacs minor mode that is aimed towards making Emacs into a top-notch Ruby and Rails development environment.
For the latest version see http://github.com/eschulte/rinari/tree/master
For instillation instruction and documentation see http://rinari.rubyforge.org
For discussion of Ruby on Rails related Emacs development see http://groups.google.com/group/emacs-on-rails
This emacs used in this screencast was build using the emacs-starter-kit available at technomancy/emacs-starter-kit.
(sorry there is no sound in this video)