[theultdev]

I never said they were still using it (they are in some cases)

But when the backend world was either Java or ASP, FB chose PHP and helped us other small companies out.

They eventually went Hack, the rest went Node for the most part.

But during those PHP years they gave us HHVM and many PHP improvements to get us through.

[captn3m0]

HHVM was not a contribution to PHP. It resulted in PHP 7 being sped up and releasing with a bunch of long awaited features. But afaik , very little of HHVM made it back to PHP core.

[theultdev]

It made PHP 5-7 usable in production, otherwise it would have died before we got to modern PHP.

Of course it wasn't merged in, it was a separate compiler, it certainly inspired future optimizations though.

But the point is, it was a very useful stop-gap solution for the community.

Also would like to highlight that they have contributed a lot to PHP upstream in addition to that.