Looks like Facebook might have inadvertently turned PHP trendy again.
Expect "Why I migrated from Go to Hack" articles soon enough.
Either way, the name is very fitting. I have no use for this, but good for Facebook that they've managed to (at least to some extent) evade some of the many PHP pitfalls.
I started web programming using PHP back in 2000, but quickly moved to Python a couple of years later and never looked back. That is, until I joined FB this year as a data engineer. Programming in PHP with Hack/XHP is awesome.
Historically XHP was developed before Hack. It's available as an add-on for PHP but never became a formal part of the PHP language. When Hack was being designed it needed to work well with XHP (as XHP is used a fair amount with Facebook's code base), so over time it made more sense to start thinking of XHP as being one the language features that Hack offers that is not available in stock PHP.
Expect "Why I migrated from Go to Hack" articles soon enough.
Either way, the name is very fitting. I have no use for this, but good for Facebook that they've managed to (at least to some extent) evade some of the many PHP pitfalls.