HipHop Virtual Machine (HHVM)

What HipHop Virtual Machine (HHVM) is

HipHop Virtual Machine (HHVM) is an open-source virtual machine for executing programs written in Hack. It compiles Hack programs into intermediate bytecode, then uses a just-in-time compiler to convert that bytecode into x64 machine code while the program runs. HHVM runs on Linux hosts and supports the x86_64 guest architecture. The Hack Typechecker is included with both official prebuilt installations and source builds.

For installation, official prebuilt packages cover several Debian and Ubuntu versions, including supported LTS releases. Users can also compile HHVM from source to use code as it is checked into GitHub. It offers two web-serving modes: Proxygen, a server built into HHVM, and FastCGI, which needs a compatible front-end web server. Documentation describes using FastCGI with Apache 2.4 through mod_proxy_fcgi and with nginx, and covers supported built-in and dynamic extensions. HHVM is free, with the listed plan priced at $0. The project says it makes changes daily and releases often, and directs users to GitHub issues for typechecker or runtime regressions. Community resources include the Hack and HHVM GitHub repositories, a Facebook Group, and project social accounts. The documentation identifies Meta Platforms, Inc. as publisher.

Who it suits

HHVM suits developers building or running Hack programs on Linux, especially those who want the Hack Typechecker included with the runtime. It also fits teams choosing between a built-in Proxygen server and FastCGI integration with Apache 2.4 or nginx.

Limits

The listed free plan costs nothing. FastCGI requires a compatible front-end web server; the documented prebuilt packages are for several versions of Debian and Ubuntu.

Getting started

1. Visit https://hhvm.com/.
2. Choose an official prebuilt package for a supported Debian or Ubuntu version, or compile HHVM from source.
3. Use the included Hack Typechecker with the installation.
4. Choose Proxygen for built-in web serving, or configure FastCGI with a compatible front-end server such as Apache 2.4 through mod_proxy_fcgi or nginx.

Verdict

Choose HHVM if you need a free, open-source runtime for Hack on Linux with the Hack Typechecker included. Look elsewhere if you need a host platform beyond Linux or do not want to provide a compatible front-end server for FastCGI.