PHP is a widely-used, general-purpose computer scripting language. Originally designed for producing dynamic web pages, it has since evolved. PHP now is especially well suited for web development and can be embedded into XHTML. It generally runs on a web server, taking PHP code as its input and creating web pages as output. (Much of the server side code for Drupal Content Management System is written in the PHP language.) It can be deployed on most web servers and on almost every operating system and platform free of charge.