Odd choice to do hardware design in scala...

I wasn't aware of any other big players doing this... I suspect it will limit the impact this project can have if industry can't adopt it easily into existing processes.

It's actually chisel. But github marks it as scala because chisel is based on scala.

Other HDL based on scala includes SpinalHDL.

These two HDL are pretty welcomed because of opensource and usability. You can find lots of projects in them. Notably rocket-chip, which is also in chisel. https://github.com/chipsalliance/rocket-chip

They're around for a while but still young and some people are pushing for adoption.