PHP is a general-purpose scripting language geared towards web development. Danish-Canadian programmer Rasmus Lerdorf created it in 1994. The PHP Group now produces the PHP reference implementation. PHP originally stood for Personal Home Page, but it now stands for the recursive initialism PHP: Hypertext Preprocessor.

The standard PHP interpreter, powered by the Zend Engine, is free software released under the PHP License. As a result, PHP has been widely ported and can be deployed on most web servers on almost every operating system and platform, free of charge.