When we look at the web applications platforms currently offered by host providers, we will see that the most prevalent is the PHP/MySQL combination.

Well supported by their respective home sites—http://www.php.net, and http://www.mysql.com —this duo has enabled developers to build a lot of ready-made open source web applications, and most importantly, enabled in-house developers to quickly put in place solid web solutions.

MySQL, which is mostly compliant with the SQL:2003 standard, is a database system well known for its speed, robustness, and a small connection overhead. This is important in a web context where pages must be served as quickly as possible.

PHP, usually installed as a module inside the web server, is a popular scripting language in which applications are written to communicate with MySQL (or other database systems) on the back end and browsers on the front end. Ironically, the acronym's significance has evolved along with the web evolution, from Personal Home Page to Professional Home Page to its current recursive definition— PHP: Hypertext Preprocessor. A blog posting about the successive name changes is available at http://blog.roshambo.org/how-the-php-acronym-was-reborn. PHP is available on millions of web domains and powers famous sites such as Facebook, Yahoo!, YouTube, and Wikipedia.