The authors use the Java JUnit library to illustrate good unit testing practices and procedures, but the material focuses more on the business of testing and less on the technical framework. Many people know the theory behind unit testing, but a periodic refresher like this is useful for those of us who don't always practice it to its full potential. The book deals with the 'why?' just as much as the 'how?' of unit testing by providing good examples of how tests will pass yet the code is still buggy, and how to remedy that for next time.
I liked the fact that I could actually follow the examples even though I don't know Java. The authors did a good job of keeping the concepts clear and concise.
I rate this book an 8 out of 10. Good work.