From the Preface:

This book is about a marriage of two compatible yet unlikely partners. Extreme Programming (XP) is a software development methodology that enables users, business people, programmers, and computers to communicate effectively. Perl is a dynamic programming language that lets an XP team embrace the inevitable change caused by effective communication. Perl is the fixer and doer of the pair, and XP is the organizer and facilitator. Together they help you build robust software applications efficiently.

Like any good marriage, the partners of Extreme Perl support each other. For example, XP asks business people to write acceptance tests, and Perl lets the business people use their own language and tools for the tests. Much of Perl only happens when the program runs, and XP asks programmers to define what is supposed to happen in unit tests before they write the program. In this book, you'll see other examples where Perl reinforces XP and vice versa. This mutual support system is what makes Extreme Perl applications robust.

This book invites Perl programmers and their customers to take a fresh look at software development. Customers, and business people in general, will learn how XP enables customer-programmer communication for efficient and flexible requirements gathering. Programmers will see how XP's focus on teamwork, incremental testing, and continuous design allows them to take pride in their craft. The numerous examples demonstrate Extreme Perl in action, including the development of a complete, end-to-end application in the last chapter.

How to Read This Book:

This book explains Extreme Perl to both programmers and business people. It also attempts to convey the Extreme Perl experience through examples and personal anecdotes. The book covers Extreme Programming (XP) in detail, so no prior experience is necessary.

If you are a top-down thinker, you're recommended to read this book front to back. Bottom-up thinkers may want to start at the last chapter and work backwards.

As noted in the previous section, the Perl code in this book is advanced. The programming examples are not complex, that is, they are short and contain only a few concepts. However, the code may appear complicated to some programmers. If you are familiar with functional programming and object-oriented Perl, the examples should be clear. If not, you may want to peek at the last chapter which describes functional programming. The references throughout the book may be helpful, too. The object-oriented aspects are not all that important, so you should be able to understand the examples without object-oriented experience.