Its official name is PHP: Hypertext Preprocessor, and it is a server-side scripting language. When your Web browser accesses a URL, it is making a request to a Web server. When you request a PHP page, something like http://www.yourcompany.com/home.php, the Web server wakes up the PHP parsing engine and says, “Hey! You’ve got to do something before I send a result back to this person’s Web browser.” Then the PHP parsing engine runs through the
PHP code found in home.php, and returns the resulting output. This output is passed back to the Web server as part of the HTML code in the document, which in turn is passed on to your browser, which displays it to you.
A Brief Chronicle of PHP
In 1994, an incredibly forward-thinking man named Rasmus Lerdorf developed a set of tools that used a parsing engine to interpret a few macros here and there. They were not extravagant: a guest book, a counter, and some other “home page” elements that were cool when the Web was in its infancy. He eventually combined these tools with a form interpretation (FI) package he had written, added some database support, and released what was known as PHP/FI.
Then, in the spirit of open source software development, developers all over the world began contributing to PHP/FI. By 1997, more than 50,000 Web sites were using PHP/FI to accomplish different tasks—connecting to a database, displaying dynamic content, and so on. At that point, the development process really started becoming a team effort. With primary assistance from developers Zeev Suraski and Andi Gutmans, the version 3.0 parser was created. The final release of PHP 3.0 occurred in June of 1998, when it was upgraded to include support for multiple platforms (it’s not just for Linux anymore!) and Web servers, numerous databases, and SNMP (Simple Network Management Protocol) and IMAP (Internet Message Access Protocol). Then the birth of PHP 4.0 occurred. No small version change, PHP 4.0 marked a complete rethinking of the PHP core and a rewrite of the internals of the scripting language itself. The PHP development team and Zend Technologies produced a remarkable product with nearly a fifty-fold performance improvement over version 3.0, with a long list of new and useful features. When PHP 5.0 was released, it marked a rather radical change for the language, including new concepts of object-oriented development and database work.
As if that weren’t enough, PHP 6 has been in the works almost since PHP 5 was released, culminating in what we have today: an even faster, feature-rich programming language suitable for procedural or object-oriented scripts, which warrants a place in the enterprise.