PHP (a recursive acronym for “PHP: Hypertext Preprocessor”, originally Personal Home Page) is a free interpreted language, originally used only for the development of present and active server-side applications capable of generating dynamic content on the World Wide Web. It is among the first languages that can be inserted into HTML documents, in many cases dispensing with the use of external files for any data processing. The code is interpreted on the server side by the PHP module, which also generates the web page to be viewed on the client side. The language evolved, started to offer functionality in the command line, and in addition, gained additional features, which allowed additional uses of PHP, not related to web sites. You can install PHP on most operating systems for free. Direct competitor of ASP technology belonging to Microsoft, PHP is used in applications such as MediaWiki, Facebook, Drupal, Joomla!, WordPress, Magento and Oscommerce.