[wwweston]

> Facebook forked PHP to make Hack to try and make PHP usable.

Facebook clearly found PHP usable before they created Hack, otherwise they would (a) not have bothered and (b) may well not have existed in the first place.

The accurate statement is probably closer to "FB created hack to adapt to performance demands at an unusual scale and add some additional typing discipline bringing additional order across a large engineering team."

[swsieber]

I'd take it one step further:

At Facebook scale, performance gains have huge returns (adding typing can improve pefromance), so they try to improve all parts of their infrastructure, not just PHP.

For example, Facebook's bolt for native code: https://code.fb.com/data-infrastructure/accelerate-large-sca...

PHP probably did have more low hanging fruit than say C, I'll give them that.