W elcome to yet another book on the great programming language of PHP. This book is unique in that it focuses on higher-end materials and more advanced, cutting-edge topics. We have kept it as modern as possible with the fast-paced world of the Internet. We take the reader from an intermediate level to a more advanced level of this great programming language.

PHP began as a project led and designed by Mr. Rasmus Lerdorf. In June 1995, he released version 1.0 of Personal Home Page Tools (its original product name). It was a small collection of functions that helped to automate the creation and maintenance of simple home pages on the then-burgeoning Internet. Since then, PHP has grown by leaps and bounds to where it is today at version 5.3.4 (at the time of writing). PHP was one of the first web development programming languages to be open source from the outset. Lerdorf was visionary enough to see the need and the potential for a tool and language that could grow with this vein of the Internet community and expand far beyond it as well.

So then, what exactly is PHP? What does it look like and “feel” like in its current version? Well, in its simplest terms, PHP is merely an HTML markup generator. If you look at the source code of a PHPgenerated web page, you will see only HTML tags; maybe some JavaScript as well, but no raw PHP code. Of course, that is an overly simplistic view of the language that has captured between 35 and 59 percent (depending on the source) of the languages in use for web development. Whatever number you settle on, PHP is the single most popular web development language on the market today.