Hiphop Virtual Machine

Install HipHop Virtual Machine (HHVM) in Ubuntu 14.04

HHVM is an open-source virtual machine designed for executing programs written in Hack and PHP. HHVM uses a just-in-time compilation approach to achieve superior performance while maintaining the flexibility and ease of use that PHP developers are accustomed to (dynamic features like eval(), rapid run-edit-debug cycle, etc). HHVM is used by Facebook to serve billions of web requests per day. To date, HHVM (and its predecessor HPHPc before it) has realized over a 9-times increase in web request throughput and over a 5-times reduction in memory consumption for Facebook compared with the Zend PHP 5.