# Plan 9 A distributed operating system developed at [[wiki/Bell Labs|Bell Labs]] in the late 1980s by [[wiki/Rob Pike|Rob Pike]], [[wiki/Ken Thompson|Ken Thompson]], and others as a successor to [[wiki/Unix|Unix]]. Plan 9 introduced concepts — including the 9P protocol and per-process namespaces — that influenced later systems design. Referenced in [[articles/Bell Labs and the Distributed Architecture of American Power|Bell Labs and the Distributed Architecture of American Power]].