PHP is a general-purpose scripting language geared towards web development. It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995. The PHP reference implementation is now produced by the PHP Group. PHP was originally an abbreviation of Personal Home Page, but it now stands for the recursive initialism PHP: Hypertext Preprocessor.
PHP code is usually processed on a web server by a PHP interpreter implemented as a module, a daemon or a Common Gateway Interface (CGI) executable. On a web server, the result of the interpreted and executed PHP codewhich may be any type of data, such as generated HTML or binary image datawould form the whole or part of an HTTP response. Various web template systems, web content management systems, and web frameworks exist that can be employed to orchestrate or facilitate the generation of that response. Additionally, PHP can be used for many programming tasks outside the web context, such as standalone graphical applications and robotic drone control. PHP code can also be directly executed from the command line.
The standard PHP interpreter, powered by the Zend Engine, is free software released under the PHP License. PHP has been widely ported and can be deployed on most web servers on a variety of operating systems and platforms.
The PHP language evolved without a written formal specification or standard until 2014, with the original implementation acting as the de facto standard that other implementations aimed to follow. Since 2014, work has gone on to create a formal PHP specification.
W3Techs reports that , "PHP is used by 77.8% of all the websites whose server-side programming language we know." It also reports that only 8% of PHP users use the currently supported 8.x versions. Most use unsupported PHP 7, more specifically PHP 7.4, while 23% use PHP 5, which is not supported with security fixes and is known to have serious security vulnerabilities.