Foreword

In 2004, Ruby on Rails became public. The world was surprised by its productivity and by the magic of Ruby that enabled Ruby on Rails. Many people knew Ruby before Rails, but few realized the power of the language, especially metaprogramming.

But Rails is not the first framework to realize the power of Ruby. dRuby came long before Rails. It uses metaprogramming features for distributed programming. Proxy objects “automagically” delegate method calls to remote objects. You don’t have to write interface definitions in XML or any IDL. dRuby is a good example of a very flexible system implemented by Ruby. In this sense, Rails is a follower.

Even though dRuby has a long history, its importance hasn’t been reduced a bit in recent years. In fact, distributed programming is getting more important. We have access to more and more computers over the Internet. In the “cloud” age, we should find a way to utilize those enormous numbers of computers. And we already have the answer: dRuby.

dRuby is not known outside of Japan as much as it should be. I hope this book helps people learn the lesser-known technology proven by history. And you will see the power and magic of dRuby and Ruby.