FOR RELEASE TUESDAY, JULY 18, 1995
MURRAY HILL, N.J. -- AT&T today announced that Plan 9,
a new computer operating system from AT&T Bell Laboratories, is
now available for research and educational use.
The Plan 9 operating system, named for the science-fiction
cult movie "Plan 9 From Outer Space," was designed
by the inventors of the UNIX® system, a widely used operating system
created at Bell Labs 25 years ago.
The product, including source code, is available for
$350. The full kit (ISBN 0-03-017143-1) will be shipped
with a CD-ROM, four diskettes and two manuals. A partial
kit (ISBN 0-03-017142-3), containing only the manuals, may
be ordered separately for $125.
AT&T is distributing Plan 9 through Harcourt Brace & Co.
The contact number in the U.S. for information and
orders is 1-800-462-8146; elsewhere, +1-415-943-4076.
The Bell Labs Research Effectiveness Division and AT&T
Software Solutions will also negotiate commercial licenses
for the new operating system.
"Plan 9 is not in competition with UNIX or Windows,"
said Paul Fillinich, marketing manager for AT&T Software
Soltuions. "It's a small, powerful system designed from the
start to work in today's distributed, networked computing world."
"Bell Labs researchers are exploring its capabilities
and working with networking products where very small size
and efficiency are essential," said researcher Allen
Eisdorfer of the Research Effectiveness Division. "We think
Plan 9 will be especially useful in a small segment of the
industry where many proprietary systems exist today."
The Plan 9 team was led by researchers Rob Pike, Ken
Thompson, Dave Presotto and Phil Winterbottom, with
contributions from others in the Computing Science Research
Center and support from Dennis Ritchie, head of the
Computing Techniques Research Department.
Thompson and Ritchie created the UNIX operating system
in 1969. "Pike and Thompson took a look and said, 'What
would we do differently if we started again?'" said Ritchie.
"The Plan 9 operating system is the outgrowth of that analysis."
The Plan 9 system is based on the concept of
distributed computing in a networked, client-server
environment. The set of resources available to applications
is transparently made accessible everywhere in the
distributed system, so that it is irrelevant where the
applications are actually running.
Ritchie noted that the Plan 9 system is not based on
the UNIX system, which pioneered multitasking computing on
small machines. "It's reworked from the ground up, and it
has no UNIX code," he said.
The Plan 9 operating system currently controls the
computer that maintains parts of the Bell Labs World Wide
Web service, including the prototype WWW 800-number
directory service, and has already been licensed to some 200
colleges and universities. It is also used in exploratory
work within AT&T.
AT&T Software Solutions Group markets and supports
software products developed by AT&T. Bell Labs is the
research and development arm of AT&T, the global
communications and computer company.
The Plan 9 Computer Operating System
from AT&T Bell Laboratories
The Plan 9 operating system is a distributed system.
In its most general configuration, it uses three kinds of
components: terminals that sit on users' desks, file servers
that store permanent data, and other servers that provide faster
central-processing units, 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 Integrated
Services Digital Network (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.
The system is divided along lines of service function.
Central-processing-unit (CPU) servers concentrate computing
power into large multiprocessors, file servers provide
repositories for storage, and terminals give each user of
the system a dedicated computer with a 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,
amortizes costs, and centralizes and simplifies management
The pieces of the system 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. 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.
Breaking the file server away from the CPU server
enhances the possibilities for security. As the file server
is a separate machine that can by accessed over the network
only by the standard protocol, and therefore can only serve
files, it cannot run programs.
The Plan 9 operating system exploits, as far as
possible, three basic technical ideas: first, all the system
objects present themselves as named files that are
manipulated by read/write operations; second, all these
files may exist either locally or remotely and respond to a
standard protocol; third, the file system name space -- the
set of objects visible to a program -- is dynamically and
individually adjustable for each of the programs running on
a particular machine.
The new operating system runs on four major machine
architectures: Intel 386/486/Pentium, MIPS, SPARC, and
Motorola 68020. It comes with its own compilers for C and
other languages, together with all the commands and program-development
tools originally pioneered in the UNIX environment.
It also provides newly designed software called Alef,
Acid and Acme. Alef provides threads, inter-process and
inter-machine communication through typed channels and
abstract data types. Acid is a programmable debugger that
understands multiple-process programs, and the programs it
is debugging may be running on a hardware platform different
from its own. Acme is a new user interface in which any
word on the screen can be interpreted as a command by
clicking on it, and any string can specify a file to be displayed.
The Plan 9 operating system was built over the past
several years by members of the Computing Science Research
Center at Bell Labs, Murray Hill, N.J., the same group that
developed UNIX, C language and C++.