Preface

Now installed on more than 20 million Internet domains around the world, PHP is the undisputed king of web programming languages. Its users cite many reasons for deployment, such as database connectivity, powerful extensions, and rich object-orientation, but nearly everyone would agree that, above all, PHP is just plain easy to use. This is the feature that continues to drive the language forward, attracting new users and enabling existing programmers to do more with their skills.

The release of PHP 5 has introduced many new features to the language, making this an exciting time for the language. Many people who had not previously considered PHP are now finding it a good fit for their needsthe new object-orientation system is a big plus, for example. More importantly, many people who had a large investment in PHP 4 are trying to migrate their code to the new release with minimum breakage. Fortunately for all of us, it's not too hard to retain backward compatibility, and it's very easy to take advantage of the many new features.

So, welcome to PHP. I think you'll find it a fun, interesting, and flexible language that might finally disprove the old saying, "Cheap, good, on time: choose any two."