HipHop is a new PHP runtime written and open sourced by Facebook that takes advantage of the fact that there are many similarities between PHP and C++.

HipHop converts PHP into semantically equivalent C++ removing the interpreted stages that can make PHP slow.This session will cover building HipHop, the minor conversions to applications to run under HipHop and how to develop your own HipHop extension.

https://www.youtube.com/watch?v=IYkIfshy_ro