Prebuilt Packages on Mint 15

To install prebuilt packages for Mint 15 (amd64), add the HHVM repository to your /etc/apt/sources.list

deb http://dl.hhvm.com/mint olivia main

Then update your package index:

sudo apt-get update

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

sudo apt-get install hhvm