PHP and MySQL Programming/Introduction to PHP
Welcome to PHP
PHP started off as a collection of Perl scripts used to aid in the maintaining of personal home pages. Hence, it originally stood for "Personal Home Page." However, the language has grown into a huge open source initiative, used by thousands of amateur and professional programmers world wide. It now is officially known as "PHP: Hypertext Preprocessor," which is a recursive acronym. (For some strange reason, open source programmers seem to love recursive acronyms...)
The reason it is known as a preprocessor and not merely as a processor, is due to the fact that the php files are sent by the webserver to the PHP preprocessor to be processed. the resulting HTML (Hyper Text Markup Language), is then sent across the internet to the web browser requesting the php page.
PHP has traditionally been used for adding dynamic content onto previously static webpages; however, due to the rapid development of the language, it is now used for writing command line tools, and now has GTK bindings allowing the programmer to write GUI applications!
Since the beginning of version 5 of PHP, with the inclusion of Zend Engine II as PHP's foundation, PHP now can be used to write Object Oriented applications.
You can download PHP free of charge (as it/is an Open Source programming language) from http://www.php.net