This book is one of the first widely available books to cover Modelica.The author Peter Fritzson has been instrumental in the development ofModelica, and the reader will benefit of his large experience and in depthknowledge of Modelica. The author has collected and enhanced material available form othersources such as the web site of the Modelica organisation. In one volume,you will find examples, reference to the language syntax and libraries,algorithm and description of some development and simulation environment.So the first benefit of the book is to be a handy single reference. The book goes beyond just being a collection of already publishedmaterial. There are a couple of chapters that provides material notavailable elsewhere or new light on existing ones. I particularlyappreciated the discussion of Modelica packages and how they compare withJava (topics that can be confusing and generally overlooked). I also foundthe chapter on applications very interesting, as it shows how Modelica canbe applied to other systems than the classical, electrical and mechanicalones. It would have been worthwhile to expand the examples on economicsand biology. There are also a lot of useful tips on modeling techniquesand the algorithm used beyond the scenes. I think that anyone with an interest in Modelica should get the book, andcurrently there is no better alternative. The book would also be usefulfor readers not necessarily interested in Modelica but with a generalinterest in Modeling and Simulation, as it does provide a lot of exampleand cover the state of the art in this field. I have removed a star, because I found at times the book confusing. PeterFritzson doesn't want to overlook any aspect of Modelica, and as such eventhe minor or more marginal topics are covered, sometimes in some details.For example, I found too much emphasis given on MathModelica and XMLrepresentation of Modelica. I think it would have been better to leavethose topics purely in Appendix and not spread them over some chapters. Ialso think the emphasis isn't always right. There are pages and pages thatdescribe the flattening process to get a flat equation model from itsModelica representation. In comparison, there is actually quite little onthe techniques used to solve this flat model (e.g. application oftopological sort, use of biparty graph to solve dependencies betweenvariables and equation, simplification based on the Pantalidesalgrorithm). It would have been worth to work a complete example through.A possible suggestion in order to keep the book small while not missingmuch of the material, would be to provide a CD with the Modelica library,the MathModelica examples. Overall a very good book that provides a comprehensive coverage ofModelica and recommended to anyone working with Modelica.