[Matl]

Isn't Hack basically compiled PHP so that it is faster for FB's use case? I understand it's not technically PHP, but I imagine it is effectively still PHP, or is it more like what C++ is to C?

I understand PHP is fast adding any actual language features that Hack has over it?

[phyrex]

At one point it was, but since then it’s become it’s own language with a completely new (JIT-based) implementation