Many of us program with object-oriented languages, such as Ruby. But what does “object-oriented programming” really mean? The emphasis in Smalltalk, the original OO language, wasn’t on objects so much as on messages — the communication that took place between the objects. In this talk, Brian Knapp explores what messages are, and how thinking in terms of them can change (and improve) the way in which you write object-oriented code — not just in Ruby, but in other languages, too.