The Modernization of PHP

Inspired and challenged by Facebook’s successes, some PHP core developers started to challenge the technological status quo. There were experiments with just-in-time compilation that showed a tenfold increase in performance, but only for synthetic benchmarks. Real-life applications like Wordpress would only show around one percent performance improvement. This discrepancy is the very reason why Facebook started Hack, and started to move towards stricter typing: without enough type information, you cannot compile PHP to efficient machine code. And PHP source code, given its origins as a loosely typed procedural language, does not really do a good job in providing a lot of type information to the compiler.

Another approach, based on a fork of PHP 5’s Zend Engine, looked far more promising. Dmitry Stogov and a team of PHP core developers had worked on cleaning up and optimizing the code. The result was a performance comparable to HHVM, with hardly any backwards compatibility breaks. This project was called PHPNG (NG being an abbreviation for “next generation”). Even for outside observers that had declared PHP as dead, and proposed JavaScript as the new king, it was apparent the PHP project was back in the game again.

It was mid-2014 when PHP 7 was born. Following the decision to skip version number 6, PHPNG became PHP 7. The PHP project aimed for a release in October 2015.

The first version of PHP 7, PHP 7.0.0, was released on December 3, 2015. It was followed by PHP 7.1.0 in December 2016, PHP 7.2.0 in November 2017, PHP 7.3.0 in December 2018, and PHP 7.4.0 in December 2019.

PHP 7.0 and PHP 7.1 have reached their end-of-life on January 10, 2019 and December 1, 2019, respectively. Until PHP 7.2 reaches its end of life on November 30, 2020, critical security issues will still be fixed for PHP 7.2 and releases will be made on an as-needed basis.

At the time of writing, PHP 7.3 and PHP 7.4 are actively maintained.

Regular releases with fixes for bugs and security issues for PHP 7.3 and PHP 7.4 will be made until December 6, 2020 and November 28, 2021, respectively. PHP 7.3 and PHP 7.4 reach their end-of-life on December 6, 2021 and November 28, 2022, respectively. Until then, critical security issues will still be fixed and releases will be made on an as-needed basis.

PHP 7.4 is the final release series of PHP 7 and PHP 8.0 was released on November 26, 2020.

PHP 5.6, the final release series of PHP 5, reached its end of life on December 31, 2018. Users of PHP 5 should upgrade to PHP 7 as soon as possible, as they may be exposed to unpatched security vulnerabilities.