Foreword

Because of PHP's humble beginning as a hackers' project – an attempt to develop an easy and enjoyable way to develop web sites – nobody expected it to become nearly as popular as it is today.

Over the years we've used many different metrics to measure PHP's popularity, looking at the number of web sites that have PHP deployed on them, the number of PHP books on sale at Amazon.com, the amount of prominent companies using PHP, the number of PHP-based projects, the size of the communities that create them, and so on.

And then, there was one other, much less “scientific” metric.

Back in 2008, when I was on my honeymoon with my wife, Anya, we stayed at a small hotel called Noster Bayres in Buenos Aires. We arrived after a long flight, visiting a brand-new country full of new faces and things we'd never seen before. Imagine my surprise when, after I filled in my hotel registration form, the receptionist asked me if I was Suraski, “that PHP guy.” It turned out that he was developing a social network for the San Telmo neighborhood in PHP.

Although all of the previous metrics were rock-solid proof of PHP's extreme reach, importance, and popularity, for me, this incident in a small hotel halfway across the world sealed the deal. If the receptionist at that hotel was writing PHP, we were most certainly mainstream.

Almost three years later, advanced PHP skills are essential to any power web developer, and arguably – with the explosive growth of web and HTTP-based communications – to any and all developers. Pro PHP Programming guides you through some of the more advanced aspects of modern PHP development, including object orientation, mobile application development, and scalable data sources that can be important for cloud-enablement. I'm sure the knowledge you'll gain will be an important part of your toolset going forward, and will help you avail of the advanced features of PHP 5.3 to their fullest. Happy PHP-ing!

Zeev Suraski, CTO, Zend