In typical Facebook fashion, the new language is called Hack, and it already drives almost all of the company's website -- a site that serves more than 1.2 billion people across the globe.

Hack requires Facebook’s HHVM (Hip Hop Virtual Machine) to run. HHVM is a virtual machine that compiles PHP, normally an interpreted language, into byte code, so it can run more quickly.

Hack has changed that, Facebook said. Thus, the company said, “Hack was born.” Facebook explained that one of the major embellishments to PHP thus: “Our principal addition is static typing.

According to Hack's website, the programming language provides "instantaneous-type checking via a local server that watches the filesystem. It typically runs in less than 200 milliseconds, making ...