Programming Ruby 1.9: The Pragmatic Programmers' Guide (Facets of Ruby)
Dave Thomas, as one of the authors of the Agile Manifesto,  understands agility.  As the author of "Programming Ruby," he understands Ruby. And, as an active Rails developer, he knows Rails.Chad Fowler is co-director of Ruby Central, Inc., and remains an active, driving force in the Ruby community.Andy Hunt is a programmer turned consultant, author and publisher. He co-authored the best-selling book “The Pragmatic Programmer”, was one of the 17 founders of the Agile Alliance, and co-founded the Pragmatic Bookshelf, publishing award-winning and critically acclaimed books for software developers.