> FB poured a ton of money into Hack/HHVM. Which didn't directly benefit PHP

Facebook may not have directly funded PHP, but I know for sure at least one of the HHVM/Hack devs (Sara Golemon)is also a huge contributor to the PHP core.

https://www.youtube.com/watch?v=TOveFBc9AyI

https://voicesoftheelephpant.com/2019/07/16/interview-with-s...