The easiest way to get going with HHVM is to use one of our supported prebuilt packages. Currently prebuilt packages are available for:
For normal usage, using a prebuilt package is the best course of action for ease of installation and stability. However, if you want to live on the bleeding edge and get the latest and greatest code as it is checked into GitHub, you can compile HHVM straight from source. Check the compilation instructions for both the supported Linux and Mac OS X distros.
If we support a prebuilt package for a distribution, we support compiling it from source as well.