Comment by pjmlp

First, we could start by what UNIX authors did after they considered UNIX done, looking at Plan 9 and Inferno.

Then there are the OSes already done during the 1960 and 1970 outside Bell Labs, as possible ideas.

As from where the software would come from, if we keep recicling UNIX, we will keep getting UNIX regardless of whatever cool features the OS might offer, as most developers are lazy.

Hence why it is great that while Apple and Google OSes have some UNIX there, bare bones POSIX apps will hardly make it into the store.