Testing is a cornerstone within the burgeoning discipline of Extreme Programming. Much has been written about XP, but to date, no book has specifically addressed the key role that the tester plays in this lightweight methodology. This new book defines how an XP tester can optimally contribute to a project, including what testers should do, when they should do it, and how they should do it. Each teaching point is supported by practical examples, helpful suggestions, and proven techniques that will help readers improve the quality of their next project. The material is based on the authors' real-world experience making XP work within development organizations. The book also provides a unique "Road Hazard Survival Kit" with copious resources that help the tester address common pitfalls. Both testers unfamiliar with XP, and XP devotees unfamiliar with testing, will benefit greatly from this book.