Plan 9 is a new computer operating system and associated utilities. It has been built over the past
several years by the Computing Sciences Research Center of Bell Laboratories, the same group that
developed Unix, C, and C++.

Plan 9 is a distributed system. In the most general configuration, it uses three kinds of components:
terminals that sit on users' desks, file servers that store permanent data, and CPU servers that
provide faster CPUs, user authentication, and network gateways. These components are connected
by various kinds of networks, including Ethernet, Datakit, specially-built fiber networks, ordinary
modem connections, and ISDN. In typical use, users interact with applications that run either on their
terminals or on CPU servers, and the applications get their data from the file servers, but it's also
small enough to run by itself on a laptop. It is highly configurable; it escapes from specific models of
networked workstations and central machine service.

Distribution

We're happy to announce the release of Plan 9. This edition is available for noncommercial use by
anyone, using a shrink-wrap license. It can be ordered just like a book; click here for information.

An earlier release of Plan 9 has been available to universities for a while, and it's gained some fans
(see below). We are no longer licensing it; the new one is much improved.