I bought this one a year ago, but there was always something easier to read so I procrastinated. This year I had a problem with getting internet connection in Spain so it was convenient to read something on paper. Book is directed to advanced JavaScript programmers and it is going to be hard for junior programmers. Some parts were hard for me as well and last three chapters (Master Training) was just complicated code samples with an only high-level overview. The best part of the book are chapters 9-12 (Ninja Training). I would expect most of the book to be at this level and with this kind of elaboration. The rest of the book was too easy or too complicated. I have expected more from the book. Differences between old IE browsers and W3C compatible ones fill most of the chapters. Authors argue many times it is more important how to do things than what actual examples, but I would prefer something more interesting. It's a good read, but you have to know a lot about JavaScri