This book is split into two parts. In part one we examine what comes shipped with the standard library in Ruby 1.8.x and Ruby 1.9.x. We look, in depth, at understanding how DRb (dRuby or Distributed Ruby) and Rinda work. We'll build some simple applications, in a variety of ways, and use those examples to talk about the libraries. We'll examine the pros and cons of DRb and Rinda. By the end of part one you should feel comfortable and ready to build your distributed applications using these libraries.

In part two of the book we'll look at a variety of different third party tools, libraries, and frameworks designed to make distributed programming in Ruby easy, fun, and robust. Some of these libraries build on the DRb and Rinda libraries we learned about in part one, some don't. Some are based around executing arbitrary code on another machine. Some are based on running code in the background to elevate performance. Others, yet, are about using message queues to facilitate communication between different processors. While we won't cover each of these third party libraries in painful details, we will cover them enough that you understand their use, their place in the world of distributed programming, and when and where you would want to use them.