There's certainly a lot of stuff inspired by Hack. If Hack did something well, sometimes PHP copies it. The syntax of all PHP 7's new type stuff is very close t

There's certainly a lot of stuff inspired by Hack. If Hack did something well, sometimes PHP copies it. The syntax of all PHP 7's new type stuff is very close to Hack's. Though the details may differ significantly. Hack and PHP's type systems are only superficially the same (AOT rather than runtime validation, disabling or ignoring type checks versus using "weak" type checks, type inference vs. no type inference, etc.), for example.