Yes www still uses hack. No we probably won't ever migrate to another language for www.
That being said, I don't think anything BUT www is written in hack.
That being said, I don't think anything BUT www is written in hack.
I was at FB a few years ending in 2020.
Wherever I work, I end up doing a fair bit of 'code/tech archeology' just for fun and curiosity's sake. While WWW is the vast majority of Hack, I did see it in active use and maintenance in a number of other areas.
Pretty interesting stuff really.