Programming is all about building layers of abstractions. As you solve problems, you're building bridges from the unrelenting and mechanical world of silicon to the more ambiguous and fluid world we inhabit. When you metaprogram, you are no longer limited to the set of abstractions built in to a programming language. Instead you can create new abstractions which are integrated into Ruby. In effect, you're creating a new, domain-specific programming language---one that's designed to let you express the concepts you need to express to solve your particular problem.

Ruby makes metaprogramming easy. As a result most advanced Ruby programmers will use metaprogramming techniques to simplify their code. This talk shows how they do it. It isn't intended to be an exhaustive survey of metaprogramming techniques. Instead we'll look at the underlying Ruby principles that make metaprogramming possible. From there you'll be able to invent your own metaprogramming idioms.