Plan 9: It Look's Familiar, But It's Gnot

The personal-workstation computing environment, as generally implemented, is impractical for a large group of close-knit users. The workstations, an important capital investment, quickly become overloaded and obsolescent, and the cost of maintaining technological parity within the group is high. The traditional time-sharing scheme of terminals connected to a mainframe achieves lower update costs per user, but the existence of a major critical component (the mainframe) means that graceful changes are impossible. In our group at Bell Labs, we have been developing a distributed computing environment (Plan 9) that avoid these problems. In Plan 9, each user has a 68020-based bitmap terminal (the gnot) connected to a 1 Mb virtual-circuit network (INCON). The network provides file and computing services on a variety of hardware. The operating system blurs the distinction between local and remote processes, giving the illusion of a large homogeneous system. Nevertheless it is possible transparently and adiabatically to add services to the network, and the network architecture allows arbitrarily large systems to be constructed.