There's a PyObjC bridge as well: http://developer.apple.com/cocoa/pyobjc.html
Re:Developing Cocoa Applications Using MacRuby
by tlrobinson on Monday October 20, 2008 @07:56PM
(#338458)
And now JavaScript: http://inexdo.com/JSCocoa
And Perl and Lua and Lisp and most other major languages: http://cocoadev.com/index.pl?CocoaBridges
I'm sure it's more complex than just that, but this does take down an entry barrier for me to developing for Macs. The next language on my list to learn is Python, so Objective-C was going to have to wait...