It's odd not including Plan 9 here. But I guess that is the fate of Plan 9.

charlesdaniels · on Jan 8, 2019

Yeah, I did not include anything without at least some recent development. AROS and plan9 both got cut for that reason.

I was on the fence about including ReactOS but wound up not including that either.

jxy · on Jan 11, 2019

I would consider 9front quite active from their Hg repo.

dralley · on Jan 8, 2019

Redox reuses a lot of concepts from Plan 9

nine_k · on Jan 8, 2019

It has already pushed the boundaries, and now seems not to be developed or used that actively.