Dev.SN

youngatheart writes:

"First there was HipHop, the PHP interpreter which improved performance, now usually referred to by the less embarrassing name HHVM. Building on HHVM, they've just introduced Hack, which 'reconciles the fast development cycle of PHP with the discipline provided by static typing, while adding many features commonly found in other modern programming languages.'

Over the past year, Facebook has converted nearly all of its PHP code base to Hack, which makes up the core of its website."