The History of PHP: Evolution and Key Milestones

PHP started out as a small open-source project that evolved gradually as more and more people found out how useful it was. Rasmus Lerdorf released the first version of PHP way back in 1994. At that time, PHP stood for Personal Home Page, as he used it to maintain his personal homepage. Later on, he added database support and called it "Personal Home Page/Forms Interpreter" or PHP/FI, which could be used to build simple, dynamic web applications.

In 1997, Zeev Suraski and Andi Gutmans rewrote the parser and laid the foundation for PHP 3. They also introduced the recursive acronym PHP: Hypertext Preprocessor. Suraski and Gutmans are also the authors of the Zend Engine, a compiler and runtime environment for PHP. The Zend Engine powered PHP 4, which was released in May 2000.

PHP 5, released in 2004, brought significant new features such as Object-Oriented Programming (OOP) support, PHP Data Objects (PDO), and numerous performance enhancements.

In 2015, PHP 7 was introduced as a major update, featuring new language capabilities, including return type declarations for functions and scalar type declarations for parameters and return types.

New Features in PHP 8

PHP 8, the latest major version, was released in November 2020. It introduced several new features and notable changes:

  • Just-in-time (JIT) Compilation: Provides substantial performance improvements for mathematical operations and the potential to move some code from C to PHP.
  • Match Expression: A more compact alternative to the switch statement. As an expression, its result can be assigned to a variable or returned from a function.

PHP 8 also introduced various type changes and additions:

  • Union Types: Allowing the specification of multiple types for a parameter or return value.
  • Static Return Type: Adding a static return type to functions.
  • Mixed Type: Introducing a mixed type to accept any type of parameter.
  • Attributes: Similar to annotations in other programming languages, allowing metadata to be added to PHP classes.

Important Milestones in PHP's Release History

Here are some key milestones in PHP's development:

Version 1.0 (8 June 1995)Officially called "Personal Home Page Tools (PHP Tools)". The first use of the name "PHP".
Version 2.0 (1 November 1997)Officially called "PHP/FI 2.0". This release featured many characteristics that define PHP today.
Version 3.0 (6 June 1998)Development expanded to multiple developers. Zeev Suraski and Andi Gutmans rewrote the base for this version.
Version 4.0 (22 May 2000)Introduced the Zend Engine, a two-stage parse/execute tag-parsing system.
Version 5.0 (13 July 2004)Featured Zend Engine II with a new object model and many new features.
Version 5.1 (24 November 2005)Performance improvements and the introduction of PHP Data Objects (PDO).
Version 6.xAbandoned version planned to include native Unicode support.
Version 7.0 (3 December 2015)Introduced Zend Engine 3, return type declarations, scalar type declarations, and more.
Version 7.3 (6 December 2018)Included flexible Heredoc and Nowdoc syntax.
Version 8.0 (26 November 2020)Introduced Just-In-Time (JIT) compilation, named arguments, union types, and more.


PHP continues to evolve, driven by a vibrant community and ongoing improvements to its performance and capabilities. The latest stable version, PHP 8.2.9, is available as of this writing.