PHP is the open source programming language that builds the backbone of SilverStripe.
PHP 5 Support
By default, CWP environments run PHP 5.6 (see Debian "Jessie" packages(external link)).
PHP 7 Support
Support for PHP 7, the latest version of PHP, was introduced with SilverStripe stable release 3.6.0, used in CWP recipe basic 1.6.0.
CWP environments can be upgraded to run PHP 7.1 via a request to the Service Desk.
The active support and security support of PHP 7 extends that of PHP 5 (see the official PHP documentation(external link)).
Amongst the many performance benefits of PHP 7 over PHP 5, are speed improvements. Benchmarking shows that a SilverStripe default project running on PHP 7 is 2 to 5 times faster compared to a vanilla PHP 5.6 installation. It is also significantly faster than PHP 5.6 with opcaches enabled.
Consider upgrading CWP to take advantage of these performance improvements for your CWP project. Download the free Upgrading to CWP 2.0 guide, including a handy 8-step checklist to get you started on your upgrading journey.