An interesting article from IBM on the Ruby extension for Eclipse, Using the Ruby Development Tools plug-in for Eclipse. The blurb:
This article introduces using the Ruby Development Tools (RDT) plug-in for Eclipse, which allows Eclipse to become a first-rate Ruby development environment. Ruby developers who want to learn how to use the rich infrastructure of the Eclipse community to support their language will benefit, as will Java™ developers who are interested in using Ruby.
Fortunately, the article is more than just a description and includes setup and all that. And what pretty screenshots!