Ruby Under a Microscope: An Illustrated Guide to Ruby Internals 1st Edition

I've meant to buy this book for ages. I wish there were books like this for every programming language. It's very readable and approachable. Not dry zzz material at all. Contrary to what he says though, you cannot really be into it unless you're peeking at the C source :)
General lessons are learnable here that apply to lots of languages too.

Great information about Ruby. Nice diagrams as well as experiments that show cool Ruby commands to peek into its internals. Highly recommend if you are interested in programming languages.

Learned things that the Ruby reference does not explain well enough. Also learned general software engineering concepts, not just Ruby. Does not cover the parser in depth, but that's expected as bison is quite complex.

Excellent read

Amazing! Excellent! Fantastic! Whee!

Very easy to read and understand.

Ruby Under a Microscope is a remarkable dissection of the internals of Ruby's runtime environment. Definitely too much for the casual user, but an absolute must for the power user - the dissection of how hash tables work in Ruby "under the hood" is worth the book in of itself. Coverage of the innards of the runtime's garbage collection process is equally useful.

The experiments the author carries out throughout the book to show the language's behavior, or to measure performance, are not only great explanation of how things operate, they are entertaining to read - at least for those with a performance tuning eye or a desire to really understand what is going on. I love it, I have seen this done in class, I have done it myself, but it is a teaching model rarely seen in writing that fits this technically deep subject very well.

Fans of lisp will appreciate the credit that the author gives the venerable language for closures and for McCarthy's garbage collection algorithm, among other things.

The book is richly illustrated, and the diagrams help a great deal in following the details being discussed - as you can imagine, pointers^Hreferences are everywhere, and diagrams really make decoding the lay of the land much easier.

A minor negative, looks like No Starch used a lighter paper choice than their regular, thick heavy paper - a fancy attribute of their books that I have come to look forward to. I would expect this was done to limit the heft of this particular tome, that at 330-plus pages would have come out rather thick in the usual paper choice.

Ruby has become a major player in application and (by extension) Web development due to the easy to acquire skills to use the language, the expansive library sets due to the open source nature and the integration and support on nearly any platform.

Me, being a Windows OS guy, I look to major references like Microsoft Press’ “Windows Internals” to understand how things really work – not just at the surface – but why something does what it does. For example, if the distributed processing calls (DPC) result in interrupts consuming the processor, I know I’m usually looking at a driver or hardware problem.

“Ruby – Under a Microscope” is much like “Windows Internals” in that the how and why of Ruby is revealed.

What should be clear from the idea of an in-depth, deep technical details book – this isn’t for the beginner, like Microsoft Press’ “Windows Internals” isn’t for the newbie Windows OS user. If you don’t know what DPCs are and what they do – knowledge of DPCs is pretty much useless. To get the full value from this book, you should already be an experienced Ruby programmer (or have depth in similar languages). What the experienced developer will get from this book is the details that will allow them to extract more power from Ruby, better understanding of why things happen, and how to better use Ruby to solve the really hard problems.

Now that we’re past the “who this book is for” part, there is one more thing to understand before you decide that this is of value to you: Exactly WHICH Ruby are we talking about? Yes, Ruby is available on nearly all platforms. However, this is because some hard working people wanted to make sure that the language was widely available, and these hard working people made it available on platforms other than what the original Ruby was developed for.

So, how do you know which version of Ruby this book is focused on? The book is focused on the Matz (Yukihiro “Matz” Matsumoto) Ruby Interpreter, written in C. Other implementations are discussed, and these are discussed in the context of how others implemented the language that Matz created in 1993.

The book treats Ruby as a science study, much like a scientist would study microbes (“…Under a Microscope”, get it?). Instead of looking at organisms, the book looks at the base elements of Ruby: The actual ‘C’ source code. If you’re a computer science major, this is nothing new. The source code is studied to understand what Ruby does to perform the tasks that you give it. As you go through the book and look at Ruby at the very base elements, you can gain a complete understanding of how computers really work. There is nothing more basic than the process of providing information to a computing machine and seeing how the actual process of creating tokens, parsing of tokens, compiling into an intermediate format, and then passing onto the virtual machine (YARV – Yet Another Ruby Virtual Machine) that interfaces at the machine level. Once the processing is complete, understanding how to receive the output, convert it back into something that the programming language can understand is absolutely vital to knowing why things work. And, probably most importantly, knowing what’s wrong when they don’t work.

This is the real goal of “Ruby: Under a Microscope”. Providing understandable information for the knowledgeable programmer to gain a deep understanding of what Ruby is, what it does, and how it attains the goals that it sets for itself. This opens the door wide open for those that want to add to the language with libraries and extensions – which is the real power of a successful language: Expansion by anyone with a great idea.