Code browsing in Ruby on Rails

I have been playing with Ruby on Rails for awhile mainly learning from
Agile Web Development with Rails book. So far, I have been content
using the SCITE editor and gedit in Linux Fedora Core 5. Now that I
have pretty much gone through the example shopping cart application in
the book, I would like to be able to browse the source code not only
for the book example, but the core Rails product as well. Is there an
editor/IDE which is freely available on linux and allows for code
browsing of parent classes, auto completion etc? I am quite familiar
with Eclipse in Java environment. Somthing similar would be quite
useful. Kindly provide links to these sources.
Thanks and regards.
Bharat

http://radrails.org/

Thanks,
Pratik

Thanks Pratik. I will check out Radrails IDE. Any other suggestions?
Bharat

There is a radrails feature for eclipse ...

http://www.radrails.org/page/download

I installed the eclipse feature using the update site. I already have
eclipse for java development so I don't need the whole radrails app. It's
just a customized version of eclipse anyway (I think).