HipHop PHP

To install hiphop-php on Ubuntu 12.04, add

 deb http://dl.hiphop-php.com/ubuntu precise main

to the /etc/apt/source.list

To add the above line in /etc/apt/source.list, you need open it using root user or by using sudo with nano editor.

 sudo nano source.list

The file opens in nano editor. Add the above line. Now,

  sudo apt-get update

Finally, you can install (or update) your package with the normal apt-get install process:

 sudo apt-get install hiphop-php

I hope it helped. Feel free to comment...

References
https://github.com/facebook/hiphop-php/wiki/Prebuilt-packages-on-ubuntu-12.04