Quanta Plus and Kate both use the same KDE editing
tools, I believe, and
they both have some ruby highlighting.
Don't forget about mentioning kdevelop. It has all the
GUI easy click tools from cvs to subversion, debug
output, file views, project template support, etc.
Kdevelop is the best free IDE KDE has. It has been
really supportive in the past, mainly because they use
it to write the KDE code in. As well as the
freebsd-kde hackers 
http://kdevelop.kde.org/
- 15 supported languages including Ada, C, C++,
Objective-C (via C support), SQL, Fortran, Haskell,
Java, PHP, Pascal, Perl, Python, Ruby, Bash, XUL
(unofficially).
- Automatic code completion and code hinting for class
variables, methods, function arguments and more.
- Source formatting, syntax highlighting and code
folding.
It is a decent IDE, and I used to use it once and a
while to try out what it had. Emacs fan though I am 
--David Ross
drossruby@yahoo.com
···
-----------------------------------------
Ruby Production Archive (RPA) - The Ruby Package
Manager
http://rpa-base.rubyforge.org
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