Foreword

Today, PHP is the most widely used programming language on the Web, with over 40 percent of all web applications written in PHP. It is installed on over 22 million domain servers (source: Netcraft), as shown in Figure F-1. The number of developers using PHP has now reached over 2.5 million. The community developing PHP is very impressive, with over 450 CVS committers who wrote a total of 1 million lines of code. The PHP community is one of the most dynamic, with thousands of people sharing code, evangelizing about PHP, supporting each other, and creating many projects such as Wikipedia, Mambo, PHP-Nuke, FUDforum, SugarCRM, and Horde, just to mention a few.

Figure F-1. PHP development timeline with usage

Its simplicity is what made PHP so successful. Simplicity equals less code. Developers and companies have been developing projects with PHP in a fraction of the time it would take another language.

There is an unacknowledged war that goes on every day in the world of programming. It is a war between the humans and the computer scientists. It is a war between those who want simple, sloppy, flexible, human ways to write code and those who want clean, crisp, clear, correct ways to write code. It is the war between PHP and C++/Java.

—Adam Bosworth
Google

The future of PHP looks very bright. Leading platform vendors such as IBM, Oracle, MySQL, Intel, and, most recently, Red Hat have all endorsed it. The new Collaboration Project initiated by Zend Technologies rallies many leading companies and community members around new open source initiatives aimed at taking PHP to the next level by creating an industrial-grade, de facto standard PHP web application development and deployment environment. The Project's first two open initiatives are:

Zend PHP Framework

This is a web application framework that will accelerate and improve the development and deployment of mission-critical PHP web applications.

Support for the Eclipse Development platform

Zend is joining the Eclipse Foundation as a Strategic Developer. It will develop, in collaboration with partners, a PHP IDE based on the Eclipse platform.

Rasmus Lerdorf, the initial creator of the first version of PHP (then called PHP/FI), and Kevin Tatroe provided the guidelines for this book. The newest author on the revision project is Peter MacIntyre, a Zend Certified Engineer with more than five years experience in PHP. Wez Furlong and Chris Shiflett have also contributed to this book. Wez modernized the "Extending PHP" chapter, and Chris brought his renowned expertise in updating the "Security" chapter.

This book is a must-have for anybody working with PHP. Some of the most recognizable names in the PHP community have contributed to it. So you know that you are getting quality information. It covers all of the important PHP topics, plus unique issues such as extending and securing PHP, and discusses newer features of XML and Objects and PDO.

—Michel Gerin
Vice President, Marketing
Zend Technologies, Inc., the PHP Company