Last week I asked on Twitter which books are essential for Ruby developers. And after talking with a few people I now have a collection of twelve books.

Let’s start with mine.

• Eloquent Ruby, Russ Olsen - A good introduction into writing concise, readable code in Ruby.
• Practical Object-Oriented Design in Ruby: An Agile Primer, Metz - A nice beginners guide into structuring your ruby code.
• Growing Object-Oriented Software, Guided by Tests, Freeman, Pryce - The TDD book. Enough said.
• Understanding Computation: From Simple Machines to Impossible Programs, Stuart - Never went to a university or never completed, like me? Than you need to get this books to learn the basics of our field.
• Ruby Under a Microscope: An Illustrated Guide to Ruby Internals, Shaughnessy - Want to understand what ruby is doing internally? You need this one.

And if you are doing lots of web development, you should also get Design for Hackers.

Thankfully Lucas and Marco also contributed to my list. Both had some books I already mentioned, so I just post the books that were missing on my initial list:

Lucas

• Ruby Best Practices, Brown
• Confident Ruby, Grim
• Working with Unix Processes, Storimer
• Patterns of Enterprise Application Architecture, Fowler

Marco

• Design Patterns in Ruby, Olsen - Doesn’t include all Gang of Four Patterns, but explains them in a nice ruby way
• Metaprogramming Ruby, Perrotta - Maybe not the best for beginners, because too much meta programming could hurt you :wink: .
• Refactoring Ruby, Fields - Sometimes a little bit tough to read, but very extensive

What are yours?