MacRuby is a version of Ruby that runs on top of Objective-C. More precisely, MacRuby is currently a port of the Ruby 1.9 implementation for the Objective-C runtime and garbage collector.
RubyObjC was written by me, Tim Burks. Prior to its development, I built a web site that documented RubyCocoa. I called it "RubyCocoa Resources" and you‘ll find it at www.rubycocoa.com.
Manually Removing Items From the OSX Finder Sidebar