HHVM is a virtual machine from Facebook providing a runtime for Hack, a language derived from PHP. It is an open-source virtual machine designed for executing programs written in Hack. The VM uses a just-in-time (JIT) compilation approach to achieve superior performance, while maintaining the development flexibility that PHP provides.
As of March 9, 2017, HHVM has been ported to the ARM environment. Max Wang provides an account of the effort to do this port in his essay How the Cyber-Elephant Got Its ARM.
Work on this system is active, but there is not yet a stable release for ARM. You can build from a latest release (3.28.2 and 3.27.3 as of September 28, 2018) or build from the master. Contributors for ARM are encouraged to join the HHVM on ARM mailing list to address questions, or to participate in the #hhvm IRC channel for discussion with developers. HHVM v3.30 will be the last release series where HHVM aims to support PHP.