What is a PHP reference implementation?

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.

What does PHP stand for?

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.

What is a complete PHP implementation?

The only complete PHP implementation is the original, known simply as PHP. It is the most widely used and is powered by the Zend Engine. To disambiguate it from other implementations, it is sometimes unofficially called "Zend PHP".

When did PHP become a standard?

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.