https://belitsoft.com/php-development-services/php7-upgrading-from-php5-perfomance-security-reasons-and-case-studies Usage statistics indicate that PHP accounts for over 80 percent of all websites, topping 240 million sites according to the Netcraft web server survey (2013). PHP 7 (2015) is the most important revolution for PHP since the release of PHP 5 in 2004. The speed and security improvements alone make upgrading to PHP 7 worthwhile. In this post, we will discuss these improvements in more details.