I love this book so much, I'm buying it again. After having spent years reading it on and off, and working every problem, I've managed to wear out the spine. Since I intend to continue to work with Oz, the fascinating language that is used as the main example, I'm going to get myself a fresh copy!Before I read this book, I had already been blown away by Scheme, C++, ML, and Haskell. I had studied Java, C#, Ruby, Perl, and a smattering of Lisp, Prolog, Erlang, and historical languages. I thought I knew just about everything about programming languages, and just wanted to learn more about constraint programming. But I found that every chapter of this book, even the ones on paradigms I thought I knew well, was fascinating.Much of the book is concerned with dataflow programming, which is a refreshing and clever addition to functional programming that works very well with concurrency. I learned a lot about different forms of concurrency, and the tradeoffs between analyzability and expressiveness. The exercises on transactions were illuminating, and relational (logic) programming suddenly makes a lot more sense.My only regret is that the chapter on constraint programming is a bare introduction. After the thorough coverage of other topics, I was left wanting to know more.I will also point out that some of the code is a bit terse, doing a little too much in too little space, with too-simple variable names, often single letters. I suspect this may have been done to fit code samples on the page. I'd like to see longer, more clearly explained versions posted on the web site. The authors were ambitions with the scope of the book, so it's hard to imagine cramming in even more careful explanations. The reader will be rewarded by exploring the exercises, and asking questions on the mailing list.