I've been following the progress of MacRuby for a few months now and was looking forward to the next release. Finally, and a month or three after it was expected, MacRuby 0.4 is here, according to the MacRuby blog.

MacRuby is, to keep it simple, an implementation of Ruby 1.9 built in Objective-C with transparent calling between the ruby and Obj-C worlds. For instance Ruby Strings are actually NSStrings in MacRuby and have all the powers of both. This along with some other neat integrations provided by the team allow you to write Mac OS X Cocoa apps using Ruby instead of Obj-C, or even a combination of both. If like me you think that Obj-C is a dinosaur that doesn't deserve a place in the modern programming world, this is great news. There seems to be a lot of momentum behind this project and I wonder if it may eventually become quite a fully fledged citizen for Mac app programmers – maybe even ultimately taking over from Obj-C for most Mac OS X development. I can but hope.

One of the many neat improvements in 0.4 is the ability to bundle the MacRuby runtime into the app itself so the user need be none the wiser, and certainly doesn't need to install MacRuby.