How can you take advantage of the HipHop Virtual Machine (HHVM) and the Hack programming language, two new technologies that Facebook developed to run their web servers? With this practical guide, Owen Yamauchi-a member of Facebook's core Hack and HHVM teams-shows you how to get started with these battle-tested open-source tools. You'll explore static typechecking and several other features that separate Hack from its PHP origins, and learn how to set up, configure, deploy, and monitor HHVM. Ideal for developers with basic PHP knowledge or experience with other languages, this book also demonstrates how these tools can be used with existing PHP codebases and new projects alike. Learn how Hack provides static typechecking while retaining PHP's flexible, rapid development capability Write typesafe code with Hack's generics feature Explore HHVM, a just-in-time compilation runtime engine with full PHP compatibility Dive into Hack collections, asynchronous functions, and the XHP extension for PHP Understand Hack's design rationale, including why it omits some PHP features Use Hack for multitasking, and for generating HTML securely Learn tools for working with Hack code, including PHP-to-Hack migration