Whether you believe XP can work or not, this book will cause you to think about software programming in ways you never had before. By now most of us are familiar with the basics of XP: simplicity, communication, feedback, and courage. At the core of the XP philosophy are the concepts of pair programming, writing unit tests before coding, and small incremental software releases. The emphasis is on quality and rapid turn around.



The book opens with a foreword by Kent Beck. He is the creator of XP, and the author of Extreme Programming Explained. "XP was conceived and developed to address the specific needs of software development conducted by small teams in the face of vague and changing requirements." What this book does is to take it one step further by showing us how to implement the controversial principles of XP. The process begins by defining the roles of the customer, programmer, and manager. Each participant must provide a symmetric piece of the XP pie. The customer: determines what is to be done and how it is tested. The programmer: designs, tests, and builds. The manager: coordinates and facilitates the interactions between customer and programmer.



The authors tell us that software analysis is done in stories. A story is a short description of how the system will behave. The requirements gathering phase consists of the customer telling a story of what the software is do. Written on 5x8 index cards these stories will be later refined, sorted by importance, and handed to the programming teams for implementation. "Stories should encompass a week or two of programmer time." Any more than a week and the story is too long, any less and the story should be combined with other stories and treated as a group. When the stories are done it is time to write the test code. Working on one story at a time the programmer writes a test for each task in a story, and then codes for that particular task until it works.



After reading this book, readers will be amazed at the simplicity of the XP system. Metrics and modeling is not really necessary in the XP world. "Success is measured in Resources, Scope, Quality, and Time." The book was written in the clear and lighthearted manner we've come to expect from the XP family. You may not be ready to embrace the change, but XP installed is both interesting and thought provoking.