My presentation will be on the topic of MacRuby. MacRuby is relevent to Ruby developers because it allows us to dive into the world of Mac OS X development using Ruby 1.9. Unlike RubyCocoa, where we would need to use both Ruby and Objective-C, MacRuby's API allows us to just use Ruby.
I will go into a brief history of MacRuby and explain just why it is important to us as Ruby developers. I will then do some live coding of a quick desktop application using MacRuby. Attendees will be able to take away from the presentation a good understanding of MacRuby and the passion to develop something of their own using it.