Book excerpt: This book builds on your knowledge as a PHP developer to provide a fast-paced, step-by-step tutorial in building Facebook applications. The book is packed with example code and demo applications, so that you can see techniques in action. Along the way we provide quick references to the most important aspects of the API, so you can refer back as you develop your own applications with the book. This book is for PHP5 developers who want to create custom Facebook applications. It assumes no knowledge of the Facebook API or Platform, but does assume that you are a Facebook user.