Ruby Development Tool for Eclipse

From Aventine Solutions

Mainly you get syntax highlighting and code formatting. I still use the command line to test code and run irb. The interface to ri would be useful, but it's to slow for me to use. There is a RegExp view (just switch to the Ruby Perspective and you'll find it) which is great for rescuing you from of regex hell.

[edit] http://sourceforge.net/projects/rubyeclipse

[edit] http://updatesite.rubypeople.org/release