Comment by lstodd
7 days ago
yea, as sibling said. p9 was not possible on pdp11. what was possible there was .. v7 and 2bsd. see https://github.com/felipenlunkes/run-ancient-unix
p9 was done when "current state of unix" was already fixed in form of aix, sysv and bsds, it suffered the same fate as say beos.
BeOS was marketed, there was an attempt. But it was a harder sell. Plan 9 on the other hand was was kept as a research project only and was restrictively licensed in the 90s when it was actively developed.