How to install PHP 7 (PHP-FPM & FastCGI) for ISPConfig 3 on Debian 8 (Jessie)
This post is from 2015. Versions, commands and links in it may be outdated. The current release is ISPConfig 3.3.2p1.
This tutorial shows how to build the new PHP 7 (Beta) as a PHP-FPM and a FastCGI version on Debian 8 (Jessie). PHP 7 is up to 2 times faster then php 5.6 and 14 times faster then php 5.0 according to the release notes.
https://www.howtoforge.com/tutorial/install-php-7-on-debian-8-jessie/