If you're speaking of code reading, I find looking at the source code of Rubinius very interesting. Ruby has so much utility wrapped up in places like Enumerat

If you're speaking of code reading, I find looking at the source code of Rubinius very interesting. Ruby has so much utility wrapped up in places like Enumerator, that you don't see a lot of examples of low-level data structure implementation in the wild. You could look at MRI Ruby, you'd be looking at a lot of C, which tells you a lot about how Ruby works, but doesn't show you much actual Ruby. That's where Rubinius is really great. You get to see how a smart team would implement Ruby... in Ruby. https://github.com/rubinius/rubinius https://github.com/rubinius/rubinius