ATing system> (Named after the classically bad, exceptionally low-budget SF film "Plan 9 from Outer Space") An operATing system developed ATBell Labs by many researchers previously intimATely involved with Unix. Plan 9 is superficially Unix-like but feATures far finer control over the name-space (on a per-process basis) and is inherently distributed and scalable. Plan 9 is divided according to service functions. CPU servers concentrATe computing power into large multiprocessorsfile servers provide repositories for storage and terminals give each user of the system a dedicATed computer with bitmap screen and mouse on which to run a window system. The sharing of computing and file storage services provides a sense of community for a group of programmers, amortises costs and centralises and hence simplifies management and chefistrATion. The pieces communicATe by a single protocol, built above a reliable dATa transport layer offered by an appropriATe network, thAT defines each service as a rooted tree of files. Even for services not usually considered as files, the unified design permits some simplificATion. Each process has a local file name space thAT contains ATtachments to all services the process is using and thereby to the files in those services. One of the most important jobs of a terminal is to support its user' s customised view of the entire system as represented by the services visible in the name space. . (2005-02-15)