> isn’t PHP on par perf wise to Hack these days? No. But I don't have any numbers, because it's been years since the two languages were directly comparable on

> isn’t PHP on par perf wise to Hack these days? No. But I don't have any numbers, because it's been years since the two languages were directly comparable on anything but a teeny tiny example program. Facebook gets big cost savings from a 1% improvement in performance, so they make sure that performance is as good as it can possibly be. They have a team of engineers working on the problem. PHP doesn't have any engineers working on performance full-time — it's impossible for the language to compete there. Hack has also removed a bunch of PHP constructs (e.g. magic methods) that are a drain on performance, so there's no way to close the gap. But that should in no way make you choose Hack over PHP. Apart from anything else, the delta won't matter for 99.9% of websites.