Over the last few years many contributions from Facebook have made it into PHP mainline 7 & 8, and we've seen respective performance gains.
Unsure how extensively they continue to use their PHP to C++ compiler internally.
Unsure how extensively they continue to use their PHP to C++ compiler internally.
At least as of two years ago, pretty much entire web-facing portion of Facebook was written in Hack (which descends from PHP, but has what feels like every syntax feature you could stuff into an Algol-like language). Hack is run on HHVM, which is a bytecode VM that can JIT compile to machine code.