"Hack" programming language, Facebook PHP

It is not only Apple, Google, Microsoft inventing new programming languages.

Hack is a statically typed programming language based on PHP,
that runs on HHVM, same JIT compiler used for PHP.
It is developed and used by Facebook.

Converting a large codebase to Hack | Lang.NEXT 2014 | Channel 9:

PHP Evolved: Facebook's New Hack Programming Language @ InfoQ

Keith Adams on PHP at Facebook, Efficient PHP with HHVM, Optional Typing with Hack

Hack (programming language) - Wikipedia, the free encyclopedia

Hack: a new programming language for HHVM | Engineering Blog | Facebook Code