MacRuby is a version of Ruby 1.9, ported to run directly on top of Mac OS X core technologies such as the Objective-C common runtime and garbage collector, and the CoreFoundation framework. While still a work in progress, it is the goal of MacRuby to enable the creation of full-fledged Mac OS X applications which do not sacrifice performance in order to enjoy the benefits of using Ruby.

MacRuby is a free software project by Apple Inc. Sources are available under the Ruby license.

[It’s the last line I find so interesting. Also, that there are so many of these sorts of efforts taking place. IronRuby, now MacRuby, Rubinius, MagLev, etc. Great stuff for the Ruby world.]