The Gnome Desktop has interesting applications that can be extended by
plugins written in Python or C. I didn’t find any information about if
is possible to write this plugins in Ruby, too.
I don’t know if these plugins can’t be written in Ruby or other
technical reasons, but we should focus to integrate better Ruby in
Gedit doesn’t recornize RHTML syntax, an icon for .rb files is still
missing, I can’t believe that I’m the one that doesn’t use Mac OS X