One of the cooler features of RubyMotion is that you can bring in your favorite 3rd-party Objective-C code. Without this ability, you wouldn’t be able to use essential libraries such as Cocos2D, Sparrow and SDWebImage. Could you imagine?
Although the process RubyMotion requires to bring this code in is easier than you’d expect, it can be tricky and sometimes technical. That being said, if you’re looking to use RaptureXML in ruby form, here’s a sample Rakefile and usage.