Also, in the sixteen years since then some of the core Plan 9 ideas like network block devices, union filesystems, user-space/user-managed mount points and othe

Also, in the sixteen years since then some of the core Plan 9 ideas like network block devices, union filesystems, user-space/user-managed mount points and other use of namespaces have indeed made it into other OSes. Perhaps not with the purity that the Plan 9 developers hoped for, but in the end we use computers to get work done.