A virtual machine for executing programs written in Hack.

Class libraries for XHP. XHP is a Hack feature that augments the syntax of the language such that XML document fragments become valid Hack expressions.

The official Hack Language specification.

The Hack Standard Library

The Hack and HHVM manual and documentation

Provides classes to use with XHP for common components of Twitter's Bootstrap library.

Syntax highlighting and typechecker integration for Hack.

Escape Velocity Nova Fix for Modern OS X

The sources for how we have built the HHVM packages.

A complete app.net library written in JavaScript. Exported as a jQuery plugin.

Autoload classes, functions, enums, constants, and typedefs on HHVM

A Hack library for writing unit tests expressively