RubyMotion allows iOS development using the Ruby language instead of Objective-C. It provides a command line toolchain and compiles Ruby code to native iOS apps. While the syntax is Ruby, the underlying classes and objects are still Objective-C/Cocoa. This allows tapping into the full iOS SDK while enjoying Ruby's more succinct syntax. The document provides an example Hello World app and demonstrates how to load images from the camera library using RubyMotion and related libraries like Bubblewrap and RMQ.