@gabrielesvelto
Yeah, same as "BSD subsystem", but at least it came with the distro, later they've made it downloadable separately from the App Store and at some point considered abandoning that port completely AFAIK.
I'm not sure what the current status is, I've given up on Mac OS X (or just OS X, or macOS or whatever they call it now 🤪) some time around 10.11.
@pogo_thepossum