The Ruby Development Tools Plugin for Eclipse v0.4.1 has been released. 
 
Download:
http://sourceforge.net/project/showfiles.php?group_id=50233&package_id=4
3880&release_id=237095

Documentation: http://213.203.244.123/rdt/doc/html/index.html

New Since 0.4.0:
---------------------------------------------------------
- Outline refresh and marker creation (via a parse) are re-generated
after a 500 ms idle period in the Ruby Editor. This speeds the
performance of the editor considerably (Think "Woah! That's fast" -
Sorry for our earlier hack of reparsing on each refresh!)
- Option to use spaces instead of tabs ("inline", not just after
formatting)
- Configurable indent level for formatting action
- Configurable filtering in the Ruby Resources View (only Ruby files, or
all files)
- Link to Editor option in the Ruby Resources View
- .gem, .gemspec, .cgi, .rhtml, rakefile and .rbw files are all now
recognized as "Ruby" files (shown in the Ruby Resources View and
editable)
- Larger set of syntax warnings and ability to toggle their creation
(since it is still currently experimental and creates some "false
positive" warnings)
- Syntax Highlighting color defaults now match the Java editor (no more
pink comments!)
- A number of bugfixes


Major Features:
---------------------------------------------------------
- Works with Eclipse 3.0
- Ruby Debugger (currently works with Ruby 1.6.8 - see the documentation
or wiki for more information on different versions)
- Ruby Resources View
  - Link to editor
  - Ability to toggle filtering to only "ruby" files
- Ruby Editor with:
  - Ruby Outline View
  - Code Completion (current script's elements and keywords)
  - Syntax Highlighting (with configurable colors)
  - Syntax Validation (Warnings and errors) toggle
  - Visual diff of current file with latest revision on disk or in CVS
- Ruby Project Wizard
 
For a more full description of what's new in this version please refer
to: http://213.203.244.123/wiki/wiki.phtml?title=Release_Plan
 
The Project Wiki is up at:
http://213.203.244.123/wiki/wiki.phtml?title=Main_Page
 
Please if you use Eclipse, take a look at this project - we're working
towards bringing the power of the JDT to Ruby. Dynamic languages like
Ruby and Python need more dynamic tools for support and to help spread
word!

Markus has done a tremendous job with this release - you have him alone
to thank for the large majority of the new content in it. As always we
encourage bug reports and feature requests so we can get a handle on
what everyone needs and wants in their ruby editor!