Plan 9 is the successor operating system to Unix produced by the same group
at Bell Labs that produced Unix.  It grew out of frustration with attempting
to adapt the Unix timesharing model to the network: the result was,
inevitably, a set of loosely connected timesharing machines that didn't
cooperate together well.  The goal of Plan 9 is to turn the *network* into
the timesharing machine.

The Plan 9 team started in the late 1980's and quickly built a system that
supported their internal needs.  Unfettered by the need for backwards
compatibility, they fixed many of the warts and problems of traditional Unix
commands and interfaces along the way, in some cases simply abandoning parts
of the system that were no longer considered useful (for instance, a TTY
abstraction).

Plan 9 systems consist of three classes of machines that communicate via a
network independent filesystem protocol (called 9P): File servers, which
contain large stores of disk and a backup facility, CPU servers that contain
fast processors and large amounts of main memory and fast connections to the
file servers, and terminals, which contain excellent graphics and audio
hardware and with which the user generally interacts.  When the user needs
to do something computationally expensive, he or she connects to the CPU
server and does it, with the results displaying back on the terminal.
Different machines on the network need not run on the same architecture.

One of the innovations of the system that allows this to happen is the
concept of an exportable, per-process namespace.  When one connects to a CPU
server, one's namespace is carried with him or her, and the view of the
filesystem on the CPU server is nearly identical to the view on the
terminal.  This includes things like environment, current directory, and
device files.  Since things like audio and graphics are implemented thru the
filesystem abstraction, they become network transparent for free without the
need for a separate protocol: when one runs a graphical program on a CPU
server, for instance, the program opens the appropriate file in /dev, which
is imported from the terminal, causing the terminal's display to respond
accordingly.  One can similarly import network devices, storage devices,
output devices such as printers and photo typesetters, specialized hardware,
etc.

A network authentication protocol authenticates processes to one another
(either on the same machine or across the network), and authorization is
handled via specifications made in files that are stored on the file server.
9P connections may be encrypted for extra security.  Typically, a user walks
up to a terminal, turns it on, authenticates and then takes over as the
"owner" of that terminal for the duration of his or her session.  The
terminal then authenticates to remote resources as appropriate.  When the
user is done, he or she simply shuts of the terminal (which has no local
disk) and walks away.

Plan 9 also supports an innovated snapshot based backup system.  Every
morning at some predesignated time, the current state of a fileserver's
filesystems is marked "copy on write" and the set blocks that have changed
since the last backup are written off to some stable storage device
(originally at the Labs this was a large magneto-optical jukebox, but these
have since been mostly replaced by large RAIDs).  The contents of that days
backups are then inserted (indexed by date) into a read-only view of the
filesystem that is exported from the fileserver via 9P.  The end result is
that this filesystem can be imported into a process's namespace and read via
standard filesystem commands, giving the effect of an ability to "cd back in
time."  Files that are accidentally deleted can simply be copied back from
yesterday's dump (assuming they're more than a day old).  Furthermore, new
versions of a file can be diff'ed against old versions, etc.  This is
significantly more usable than the traditional Unix model of having to mount
a table, read a tar or dump file from it, and then extract files from that.

Plan 9 is available free of charge under the Lucent Public License, which is
closely modeled after the GNU GPL.

More information on it is available at:

http://plan9.bell-labs.com/plan9/

4 responses total.

I don't know if this is the proper place (I will post to 9fans later on), but
I am having trouble running Plan 9 in vmware (on XP). When I run it on the
laptop, I have no trouble at all, but in vmware, there is no grey background
and the windows are invisible. If I click the bottom window (during
installation) the the main window goes invisible. Another problem is that the
text doesn't scroll. Everything gets jumbled and I can't read anything. I have
tried many different resolutions and color depths. I haven't found anything
online that might describe my problem. Any ideas would be greatly appreciated.
Thanks in advance.

What version of VMWare are you using?  Have you searched the 9fans archives
at http://9fans.net/archive/ ?  You'd probably be better off asking on
9fans, if there's no answer in the archives; I think I'm the only 9fan on grex
and I don't use VMWare.  :-(

I thought It's a good Idea to post It here.

Searching for some notes about Plan B in LSUB -
http://lsub.org/ls/research.html -  Universidad Rey Juan Carlos of
Madrid; I found documents related to Second International Workshop on
Plan 9, that took place in Bell Labs, Murray Hill NJ, US, on the 3rd and
4th of December, 2007.

LSUB also provide video presentations to these meeting, beside Francisco
Ballesteros [e.g. Notes on the Plan 9 3rd edition Kernel source] and
several others that I recognize from books and other documents; Dennis
M. Ritchie was giving a speech about: Unix and Beyond: Themes in
Operating System Research.

http://lsub.org/iwp92007 - IWP9-Ritchie.mov - time: 56:60

Greetings from Poland,
Marcin
 

Dzien dobry.

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