> I thought green threads share memory but Erlang processes do NOT share memory, which is what makes Erlang so unique.

Erlang processes don’t share memory because the language and vm don’t give primitives which let you do it. They all exist within the same address space (e.g. large binaries are reference-counted and stored on a shared heap, excluding clustering obviously).

> Did Erlang create a so called “green process”?

Yes.

> If so, why can’t this model be implemented in the kernel?

Because erlang processes are not an antagonistic model, and the language restricts the ability to attack the VM (kinda, I’m sure you could write NIFs to fuck up everything, you just don’t have any reason to as an application developer).