Hack might be better from a language design point of view, but most people outside of Facebook seem to have lost interest in it once PHP 7 caught up to it performance-wise.

With Hack's extensive static type checking and even contexts / coeffects, it's much more than just performance. The bigger your system grows, the more pain it removes.

You still can mix it with plain PHP, much like you can mix TypeScript with plain JavaScript.

I wish high-profile PHP projects, like Nextcloud, migrated to Hack eventually; it can be done piecemeal.

> With Hack's extensive static type checking and even contexts / coeffects

Have you used contexts/coeffects?

My understanding is that it's still yet to be fully rolled out to WWW, and nobody outside FB has yet played around with it. IMO it still has some DX issues (https://github.com/facebook/hhvm/issues/8828) and the examples given in documentation don't actually work in real life (https://github.com/hhvm/user-documentation/issues/1016).

Not extensively; rather, I had to pay attention to the limitations that a particular context enforces.

It's definitely a fresh feature, iirc rolled out last winter.

Ironically, Nextcloud is moving to Golang.

https://github.com/nextcloud/server/issues/16726

In fact, if you read the discussion, you'll find there are no plans of moving from PHP at all. Nextcloud is not moving to Go.

Oops, you are right, I confused it with ownCloud

Hacks language is better, nobody will deny it. But outside of facebook there is barely no community, not many big open source projects. And as the language is now incompatible you even may not be able to use php libraries.

That sounds right, but probably at considerably lower cost.