The document discusses RubyMotion, which is a dialect of Ruby that allows developers to build iOS and macOS apps. It can access native iOS/macOS APIs through the Objective-C runtime. The document outlines why developers might choose RubyMotion, including that it allows building mobile apps using a familiar Ruby syntax. It also discusses the RubyMotion community, which includes hackers, students and professionals who enjoy collaborating and learning together through various community resources like meetups, IRC, and blogs.