hhvm
A virtual machine for executing programs written in Hack.
HHVM is a runtime that executes Hack, a statically-typed language for web development. It uses just-in-time compilation to translate code into machine code at runtime for better performance.
HHVM is an open-source virtual machine — a runtime environment — for executing programs written in Hack, a programming language developed by Meta (Facebook). A virtual machine in this context is the software layer that reads and runs code, similar to how the Java runtime executes Java programs. HHVM uses just-in-time compilation, which means it translates Hack code into machine code at runtime rather than ahead of time, aiming for better performance while keeping the development experience flexible.
Hack is a statically-typed language designed for web development. HHVM is designed to run alongside a web server: it includes a built-in server called Proxygen, or can work with nginx or Apache via the FastCGI interface. Standalone Hack scripts can also be run directly from the command line.
HHVM can be installed from prebuilt packages or compiled from source. It is licensed under the PHP and Zend licenses, with the Hack typechecker and standard library under the MIT license.
Where it fits
- Build high-performance web applications using Hack's static typing and modern language features.
- Run Hack scripts from the command line for automation and scripting tasks.
- Deploy web services with built-in Proxygen server or integrate with existing nginx/Apache infrastructure.