Plan 9 (2nd Edition) from Bell Laboratories FAQ

Newsgroups: comp.os.plan9,comp.os.misc,comp.answers,news.answers
From: (Steve Kotsopoulos)
Subject: Plan 9 from Bell Labs 2nd Edition - Frequently Asked Questions [FAQ]
Summary: FAQ for the Plan 9 2nd Edition operating system
Organization: FYWSS
Expires: Jun 7, 2000
Followup-To: poster

Archive-name: comp-os/plan9v2-faq
Last-modified: June 14, 2000
Posting-Frequency: never
Update-Frequency: never

This document answers frequently asked questions about the 2nd Edition of the Plan 9 operating system. Much of it was rendered obsolete with the June/2000 release of Plan9 3rd Edition, but it is being saved as a reference. It is unlikely to be updated anymore.

For up-to-date information, see

A hypertext version of the FAQ is available on my Plan 9 web page, URL

Other sources of information include the newsgroup comp.os.plan9, which is bidirectionally gatewayed to the 9fans mailing list (mail to subscribe or request archived messages) and of course the Plan 9 homepage at Bell Labs, URL

Please forward any comments or suggestions regarding this FAQ to


Hardware and Software:

Installation and Administration:

General Information:


Subject: What is Plan 9?

Plan 9 is a new computer operating system and associated utilities. It has been built over the past several years by the Computing Science Research Center of Lucent Technologies 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 other 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. The design, however, is highly configurable; it escapes from specific models of networked workstations and central machine service.

Subject: What is in the latest Plan9 release?

The press release for the third release of Plan9 is at
Among the changes in this release of Plan 9 are a revised kernel, which now has the means to resolve ambiguous file names; an improved graphics environment; an updated command set; and expanded libraries. The system's creators also have installed "plumbing," a new mechanism for passing messages between interactive programs, as part of the user interface.

Subject: What are Brazil and Inferno?

The first release of Plan 9 was in 1993, and was only available to universities.

In 1995 the second release was available for purchase under a shrink-wrap license.

Brazil was the next research project after Plan 9 release 2. The kernel data paths have been re-architected to take advantage of faster machines and networks.
On June 7, 2000 Brazil was released under an open source agreement. This third release of Plan 9 is available for download at

Inferno is an operating system for delivering interactive media to its users. It is intended to be used in a variety of emerging network environments, for example in TV set-top boxes attached to cable systems, advanced telephones, hand-held devices, and inexpensive networked computers, but also in conjunction with traditional computing systems.
Inferno customer support has recently been taken up by Vita Nuova.
The research version of Inferno is still described on the Bell Labs server at It appears the free evaluation version is not available any more.
The Inferno mailing list archive is at

Subject: What is its relation to other operating systems?

Plan 9 is itself an operating system; it doesn't run as an application under another system. It was written from the ground up and doesn't include other people's code. Although the OS's interface to applications is strongly influenced by the approach of Unix, it's not a replacement for Unix; it is a new design.

Subject: What are its key ideas?

Plan 9 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 first two of these ideas were foreshadowed in Unix and to a lesser extent in other systems, while the third is new: it allows a new engineering solution to the problems of distributed computing and graphics. Plan 9's approach means that application programs don't need to know where they are running; where, and on what kind of machine, to run a Plan 9 program is an economic decision that doesn't affect the construction of the application itself.

Subject: What are the advantages to this approach?

Plan 9's approach improves generality and modularity of application design by encouraging servers that make any kind of information appear to users and to applications just like collections of ordinary files. Here are a few examples.

The Plan 9 window system (called 8½) is small and clean in part because its design is centered on providing a virtual keyboard, mouse, and screen to each of the applications running under it, while using the real keyboard, mouse, and screen supplied by the operating system. That is - besides creating, deleting, and arranging the windows themselves - its job is be a server for certain resources used by its clients. As a side benefit, this approach means that the window system can run recursively in one of its windows, or even on another machine.

Plan 9 users do Internet FTP by starting a local program that makes all the files on any FTP server (anywhere on the Internet) appear to be local files. Plan 9 PC users with a DOS/Windows partition on their disk can use the files stored there. ISO 9660 CD-ROMs and cpio tapes all behave as if they were native file systems. The complete I/O behavior and performance of any application can be monitored by running it under a server that sees all its interactions. The debugger can examine a program on another machine even if it is running on a different hardware architecture.

Another example is the approach to networks. In Plan 9, each network presents itself as a set of files for connection creation, I/O, and control. A common semantic core for the operations is agreed upon, together with a general server for translating human-readable addresses to network-specific ones. As a result, applications don't care which kind of network (TCP/IP, ISDN, modem, Datakit) they are using. In fact, applications don't even know whether the network they are using is physically attached to the machine the application is running on: the network interface files can be imported from another machine.

Hardware and Software:

Subject: What platforms does it run on?

The Plan 9 kernel and applications are highly portable. Plan 9 runs on four major machine architectures: Intel 386/486/Pentium, MIPS, SPARC, and Motorola 68020. Data structures and protocols are designed for distributed computing on machines of diverse design. Except for necessarily machine-dependent parts of the kernel, the compilers, and a few libraries, there is a single source representation for everything.

The systems supported under each architecture are:

386, 486, Pentium and clones
see the "What PC hardware works well with Plan 9?" section of this faq for more information on this popular topic
MIPS Magnum 3000, 6280, SGI Power Series, Indigo, Challenge M;
SLC (4/20) Sparcstation 2 (4/75) have been tested, Sparcstation 1 (4/60), IPC (4/40), 1+ (4/65), ELC (4/25), and IPX (4/50) will probably work too;
Gnot, 68040 NeXTstation.

More details are available in "The Various Ports" at URL

Subject: Is anyone working on a port for my system?

Steve Kotsopoulos has a preliminary SGI Indy R4000 port, available from Bug reports welcome at Charles Forsyth has found that the Indy R4600 will require more extensive changes.

Both David Hogan and forsyth (separately) ported an older version of Plan 9 to the Sun-3/50 and 3/60. David Hogan got the new release working on Sun-3/50 and 3/60s and forsyth has tidied it up for distribution. See

David Hogan is also working on a port to the DEC Alpha architecture. He will announce it when it is ready.

Charles Forsyth is working on a Plan 9 Port to the BeBox, details are at A PowerPC compiler suite for Plan 9 has been implemented, see for details.

Neither the Amiga nor Atari are supported.

The Decstation 2100 and 3100 are not supported, but Tad Hunt has started working on a port. Step one was to make the plan9 mips toolset output little endian code. His patches for vl(1) to make bootable pmax code are at
Queries to

Subject: Does it support symmetric multiprocessing?

Yes. SGI Power series multiprocessors are supported both as CPU servers and file servers. The newer SGI Challenge series of multiprocessors and dual processor Pentiums are only supported by Brazil, not Plan 9.

Subject: Is it object-oriented?

No, not in the conventional sense. It is written in a strict dialect of ISO/ANSI C. In a wider sense, its general design of making all its `objects' look like files to which one talks in a well-defined protocol shows a related approach.

Subject: What about applications and tools?

Plan 9 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. Alef is a new language that 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.

Subject: What about application portability?

Plan 9 comes with a library that makes it easy to import POSIX-conforming applications. There is also a library that emulates the Berkeley socket interface.

Subject: Is there a fortran compiler?

No, plan9 does not have a fortran compiler. If you have fortran programs you want to run, you can try using the f2c (fortran to C) converter available at

Subject: What resources does it need?

As might be expected, the answer depends on what you want to do. The kernel, the window system, and the basic applications will run comfortably on a PC with 8MB of memory. A single diskette can hold the kernel, window system, editor, and basic Ethernet/Internet interface. A 4-diskette set holds a system sufficient for simple program development (compiler, loader, debugger, more utilities).

On the other hand, the system can grow. The installation at Bell Laboratories includes multiprocessor SGI Power Series and Challenge machines as CPU servers, and a 350GB Sony WORM disk jukebox for the file server.

Subject: What GUIs does it support?

The standard interface doesn't use icons or drag-n-drop; Plan 9 people tend to be text-oriented. But the window system, the editor, and the general feel are very mousy, very point-and-click: Plan 9 windows are much more than a bunch of glass TTYs. The system supports the graphics primitives and libraries of basic software for building GUIs, and if need arises, the X window system has been ported to Plan 9. [Note: The X server only runs on MIPS systems. No one at Bell Labs is working on the port, so they didn't ship it with the CDROM]

Subject: Does Plan 9 have any Unix-like terminal emulators?

The Plan 9 window system doesn't obey any inline cursor controls, since none of the native applications use cursor-addressing. If you want to get from Plan9 to Unix systems, you can run /bin/hp in one of your windows, telnet/rlogin to Unix, and set the term/TERM variable to hp2621 on the Unix end. See hp(1) for more details.

Subject: What character set does it use?

The character set is Unicode, the 16-bit set unified with the ISO 10646 standard for representing languages used throughout the world. The system and its utilities support Unicode using a byte-stream representation (called UTF-8) that is compatible with ASCII. On Plan 9, one may grep for Cyrillic strings in a file with a Japanese name and see the results appear correctly on the terminal.

Subject: What about security and user authentication?

Plan 9's authentication design is akin to that of MIT's Kerberos. Passwords are never sent over networks; instead encrypted tickets are obtained from an authentication server. It doesn't have the concept of `set UID' programs. The file server doesn't run user programs, and except at its own console, it doesn't allow access to protected files except by authenticated owners. The concept of a special `root' user is gone.

Subject: How does it communicate with other systems?

The distribution includes a u9fs server that runs on Unix-compatible systems and understands the native Plan 9 remote file protocol, so that file systems of Unix machines may be imported into Plan 9. It also includes an NFS-compatible server that runs on Plan 9, so that Plan 9 file systems may be accessed from other systems that support NFS. It includes the full suite of Internet protocols (telnet, rlogin, ftp).

Subject: Is it suitable for real time control?

No, it is not. It is a general purpose system, without an interrupt priority scheme or real scheduler.

Installation and Administration:

Subject: What PC hardware works well with Plan 9?

If you don't want to spend time fiddling with and swapping PC hardware, you may prefer to buy hardware that is in use within Bell Labs. If so, have a look at the "What We Use" document by, at

The general recommendation would be for a 486 PCI+ISA motherboard with I/O on the motherboard that would take a DX4-100. SIS or Intel chipset should be OK. If you can afford it, Intel cpus have larger primary caches and less possibility of running into incompatibilities.

A condensed summary of the hardware that is known to work follows:

AMI Enterprise IV, ACER AP41. Many people run on stock PC-clones such as Dell, Gateway, Micron Millenias
Pentium motherboards
ASUS PCI/E-P54NP4, Gigabyte GA586-ID, Tyan Tempest S1462
VGA cards/chips
S3 80[15], S3 928, S3 864, S3 964, S3 Trio64, S3 Trio32, Tseng Labs ET4000, Tseng Labs ET4000/W32p, Tseng Labs ET4000/W32i, ARK2000pv, CL-GD542x, CL-GD543x, C&T65540, MACH32, MACH64.
IDEK 8617, Viewsonic 17, Nokia 445X, Nanao Flexscan 6500 21" greyscale.
SCSI Controllers
Buslogic controllers have been the most trouble-free, due to their open policy on providing programming information. Adaptec 1542 series, Ultrastor 14F ISA and a 34F VLB.
2x Toshiba 3401, 4X Toshiba 3601B, NEC 74 and 3Xi, 4x Plextor 4-Plex. The Toshiba and Plextor let you read the digital audio over the bus.
Mitsumi, Panasonic and Matsushita, attached to a Sound Blaster audio card, 4X Toshiba 5302B, Mitsumi FX400 and Teac 6x drive, attached to an ATAPI controller. Avoid Sanyo, it doesn't execute the drive diagnotics command properly.
Sound Blaster 16 or compatible (not the Sound Blaster Pro).
PS/2 or serial, as long as it has 3 buttons.
Ethernet Adapters
3Com 3C509, 3C509B are recommended. The EISA 3C579 works, but isn't worth the extra cost. The PCMCIA 3C589, PCI 3C590 and PCI 3C595 (fast ethernet) also work. AMD 79C970 based adapters seem to work fine. SMC (WD) series up to the Elite (and the Elite Ultra), some NE2000 compatibles (including an NE4100 PCMCIA card) and one Eagle NE3210 EISA card. The 3Com 3C503 does not work at all under load. The 3Com 3C595 is not supported.

If you have time for netnews, the OS/2 and Linux newsgroups probably have some useful information.

Another useful web page on PC hardware (with a BSDi bias) is "PC Hardware Hints and Kinks" at

Subject: How do I Install Plan 9?

The installation is designed to be run from a PC. Note that Plan 9 uses an unallocated portion at the end of the disk, and you won't see this partition with the FDISK program.

  1. Back up your system.
  2. Make sure you've backed up your system.
  3. Read "Installing the Plan 9 Distribution" at URL
  4. Check the errata page at for problems and fixes found since the distribution was frozen. More recent bugfixes are now distributed in boddle format from the update directory at
  5. Here are some more questions that have been answered on the 9fans list:
IP configuration
ndb/cs will set the sysname if you setup an appropriate entry in /lib/ndb/local. You must specify an 'ether=' entry, and the address should be all lower case. If all goes well, ip/ipconfig will then configure IP.
If aux/mouse is having problems guessing the protocol, you can use the undocumented '-d type' option to help it out. Use 'aux/mouse -dC $mouseport' for a Logitech type C mouse, '-dW' for a Logitech type W mouse, or '-dM' for a Microsoft compatible mouse.
Name Service
If you have having problems, first check that ndb/dns is running. It needs to be started in /rc/bin/termrc or /rc/bin/cpurc. Also note that only fully qualified names are supported, and there isn't a separate resolver.
Binding and Mounting Devices
Note that # is the shell comment character, so you must enclose it in single quotes. For example: bind -a '#R6' /dev
Auth Server
When booting a cpuserver without an auth server, if you give as the auth server address instead the cpu server's own address, you won't have to wait for it to timeout.
Subject: How can I install only part of the CDROM?

The cdrom has about 375Meg of files on it, but if you are short on disk space you can install with much less than that. Each of the toplevel architecture-specific directories takes up over 40Meg, so if you only have PC's you can save over 140Meg by simply not installing /mips, /sparc and /68020. If you don't need the source in /sys/src (shame on you), you'll save 43Meg.

The pcdist disks at contain bugfixes that are not on the CDROM, and some of the fixes are not yet available in source form either. If you are installing on a pc, it is probably easiest to install the pcdist first, and then merge in whatever you want from the cdrom.

If you use mkfs to copy the cdrom, you can make sure you don't overwrite files that were fixed on the pcdist. You can use the following steps to load the entire cdrom except /mips, /sparc and /68020 on a standalone pc. First, install the latest pcdist using the standard installation procedure. Next, mount the cdrom [this assumes scsi cdrom at device 4]

 % 9660srv
 % disk/kfscmd allow
 % mkdir /n/cd
 % mount /srv/9660 /n/cd '#R4/cd4'
Use the following to copy the filesystem rooted at /n/cd (the cdrom) to /n/kfs (the local PC filesystem), according to the proto file /tmp/386allproto, and without overwriting any files that are on the pcdist.
 % /n/cd/386/bin/disk/mkfs -v -s /n/cd /tmp/386allproto

Where /tmp/386allproto is the following mkfs proto file:

Subject: Will Plan 9 install on disks larger than 2 Gig?

The Bell Labs distribution is getting old and will not install reliably on [E]IDE disks >2GB (you might get lucky if your disk is <4GB, but no guarantees).

Use a 2GB or smaller disk for now. Someday a patch might be available.

Subject: Are there any known problems?

New pcdist files are available via ftp from These should fix most problems people have had with disk configurations. There are also VGA fixes and ATAPI CD-ROMs are included in the list of supported hardware.

Some of the source changes are available as boddles in the update directory already but not all changes are there yet.

Problems with Adaptec 1542C[FP]
If the BIOS is enabled on the 1542C/CF and BIOS options for support of drives > 1Gb, dynamic scanning of the SCSI bus or more than 2 drives under DOS 5.0 are enabled, the BIOS disables accepting Cmbinit to protect against running with drivers which don't support those options. In order to unlock the interface it is necessary for the driver to read a lock-code using Cextbios and write it back using Cmbienable; the lock-code is non-zero.
If any of the options mentioned above are on, timeout errors will occur. Either the BIOS or all the relevant options should be disabled. There is a new version of on in the pcdist subdirectory which should overcome this problem but it's not known if it works in all cases.
Adaptec AHA-2xxx series controllers
There is no support for any Adaptec AHA-2xxx series controller. It would be great if someone wrote a driver since these are popular and show up embedded on motherboards. However, it's completely different from any other Adaptec controller and the rumour on the street is that a driver would be a fair amount of work. Manuals are hard to get, they seem to be permanently on back-order. If someone wants to tackle this project, the driver for FreeBSD may be a good starting point.
The NCR8xx series look to be a cheaper alternative with similar performance and Nigel Roles has already written a driver for it which is available at along with some other plan9 software.
3C509B ethernet card
Make sure you disable the Plug-and-Play option and set the transceiver type explicitly(don't use auto-select mode)
Subject: It doesn't work for me, how should I troubleshoot?

If you are having having SCSI problems, check your cables and terminators. this is generally the single largest cause of weird SCSI problems. Active terminators are best. If you run external cables you need to get high quality ones. Also, don't crank of the speed on the card.

Subject: How do I setup the VGA?

Simple vga cards and monitors should work at 640x480x[12]. For higher resolutions, especially on untested cards, you will have to find out more about the card so you can configure it. The relevant manuals are: vga(3), vgadb(6), vga(8), and For a detailed debugging guide (too large to include here), see

Subject: How do I control the services that start at boot time?

This is controlled by shell scripts, that are roughly equivalent to the /etc/rc files on Unix:
/rc/bin/termrc for terminals
/rc/bin/cpurc for cpu servers

See cpurc(8) for more details.

Subject: How do I setup network services?

For UDP services, you must start them up in the appropriate cpurc(8) file. For TCP, IL, or Datakit services, you must use the listen(8) daemon.

Subject: How do I upgrade from the old release of Plan 9?

The 9P protocol has changed in the second edition, due to changes in the way that Plan 9 does its authentication. For those using Unix-based u9fs file servers, you will have to compile and install the new version of u9fs. For more tips on running with a u9fs file server, see

For those using the standard Plan 9 file servers, reports that the disk format in the new release is the same, so there should be no problems running the new FS code on old disks.

Subject: How do I install Plan 9 on a standalone Sparc? (Alex Bochannek) did it as follows:

1) Unpack the CD on a UNIX system and install a u9fs server.
2) Boot the SPARC off the u9fs server
3) Create a kfs on sd1 and unpack the whole CD on it.
4) Copy the file /sys/src/9/ss/sscd to /sys/src/9/ss/sssd1
5) Change the line k9660srv.root to kfs.root and change the line boot
   terminal #R6/cd6 to boot terminal #w1/sd1
6) Add sssd1 to the CONFLIST and change CONF=ss to CONF=sssd1 in the
7) Do a make all in /sys/src/9
8) Copy the new image 9sssd1 to your favorite TFTP server (or boot
   from sd3 on your local system)
Subject: How do I install Plan 9 on a Next?

For a summary of how (Ta-Wei Li) did it, see

Subject: How do I setup a dual boot for Plan 9 and Windows95?

For a summary of how (Castor Fu) did it, see

Subject: Can I install Plan 9 with less than 8Mb of ram?

The official answer is no, 8Mb is the minimum supported memory configuration. Some people are using it with only 4Mb though.

You'll need to borrow 4Mb from another system to get you past the install process (where 8Mb is needed to expand the diskettes). After the install is done, you may be able to run with only 4Mb if you set the vga at a low resolution and/or depth, or perhaps fiddle with the kernelpercent parameter in plan9.ini(8).

Subject: How do I stop 8c/8l from running out of memory?

In /sys/src/9/pc/mem.h, SEGMAPSIZE is set to 16 (Meg) by default. If you try to compile ghostscript or libtiff on a PC, this value is too low. Change it from 16 to 64; build and boot a new kernel with this setting; and you should be fine after that.

Subject: Are there any security concerns I should be aware of?

If someone sets up their plan9 system according to the manuals, anyone on the internet can telnet/rlogin in as 'none' without a password

To disable this anonymous access, use the undocumented '-N' option to aux/telnetd and aux/ftp, which disallows logins as 'none'.

Since aux/rlogin execs aux/telnetd without the '-N' option, the only protection may be to patch the source, or remove /bin/service/tcp513

Finally, ip/tftpd grants access to any world-readable file. The main concern here is that people using u9fs as their file server probably have an /etc/passwd file from their Unix system accessible. If so, make sure you don't have any encrypted passwords in it, or someone could steal it and use 'crack' to break the passwords.

Subject: What is a boddle and what is it good for?

It's a bundle o' diffs: an rc script that when run with appropriate options will apply a set of changes to the reference copy of the source from the CDROM producing an updated copy in a subdirectory, for you to cat and diff, and eventually cp onto the active source for a subsequent mk.

The boddle command (not in the release, fetch it from takes a reference source and an updated version and produces a boddle file. it comes with a manual page; read that for details.

Subject: How do I setup PPP?

First, apply the changes at These add -9 (enable IL/IP compression) and -m (set netmask) options to pppclient, and fix a few bugs. Assuming you will use /dev/eia1, login to the ppp server as follows:

 1. % telco -s 38400 /dev/eia1
 2. % con -r -l telco!967-1111
 3. login and startup ppp on the server
 4. use "control \" to escape back to the >>> prompt in con, and type
 to link pppclient to the remote server.

 onppp is the following rc script:

{sleep 5; echo add >'#P/iproute' }&
exec aux/pppclient -i -p $*

 5. To shut down, use
	% kill pppclient | rc
    and disconnect in con.

Thanks to and for this section.

Subject: Where can I get unzip and gzip for Plan 9?
you might need to use the -f (force) option with gzip, because it changes behaviour based on isatty()

Subject: How do I use texinfo on Plan 9?
To use texinfo, run "tex foo.texinfo" to create foo.dvi, then use "dvips foo.dvi >" to create a Postscript file, which is viewable with "page" and printable with "lp". Note: If the file foo.texinfo contains cross-references, you may have to run "tex foo.texinfo" twice. The first pass creates aux files and the second pass reads them.
Subject: How do I reboot my system?
The system can be rebooted by typing ^T^Tr (two control-T's followed by 'r'). Cpu servers can be rebooted by typing ^P on the console. See the cons(3) manual for more details.
Subject: How do I tell if a file server is up?
It won't respond to ping (no icmp), but it does support arp. Of course, you could just try connecting to it with 9p.

General Information:

Subject: Where did the name come from?

It was chosen in the Bell Labs tradition of selecting names that make marketeers wince. The developers also wished to pay homage to the famous film, "Plan 9 From Outer Space".

Subject: How can I Obtain Plan 9?

Complete information for purchasing the Plan 9 distribution or ftp'ing the free PC trial version is available at URL

To summarize the information on the above webpage:

The Plan 9 distribution consists of two books, four 1.4 megabyte floppies, and a CD-ROM. The books contain the manual pages and a collection of papers describing the system.

The four floppies contain a complete bootable Plan 9 system for IBM-compatible PCs (>=386). They have the kernel, the window system, Internet support, and programming environments for both the C and Alef languages. The CD-ROM contains everything: kernels, libraries, and utilities for the Intel 386 (including 486 and Pentium), Sparc, 68020, and Mips architectures and the sources to create them. It also has a selection of interesting stuff (road maps of the US, sky catalogs).

To find out whether Plan 9 supports your hardware, read "The Various Ports" at URL

To Order

The distribution is published by Harcourt Brace and Company. To order it from the US call 800 782 4479.

From Canada and the Caribbean, call 800 841 9938

Elsewhere, use +1 407 345 3800
If you are having problems getting through on the above number you can fax your order to +1-407-345-4060.

The cost for the full kit is US$350 plus shipping; the ISBN is 0-03-017143-1. The manuals can be ordered by themselves for US$125 plus shipping; ISBN is 0-03-017142-3. Everyone, even Lucent Technologies employees, must order the system this way. There are no special arrangements or deals.

Any bookshop should be able to order it for you if you give them one of the ISBN numbers.

Free Trial
Plan 9 does not purport to run on all PCs. Since Plan 9 does not use the BIOS, it is sensitive to hardware differences between PCs. Therefore, the developers provide the contents of the four floppies on the Internet via FTP for you to try out. Ftp to, log in as anonymous, and get the files from /plan9/pcdist
Subject: How can I get involved?

The best way to learn about the system is to write something that other people in the Plan 9 user community could use, or to port the system to new platforms. Several people have already made their applications available, such as an http server, Unix-based authentication server, fileserver port to the PC, etc. The current list of user-contributed software includes: (Pace Willisson) has ported the Plan 9 authentication server to Unix, to allow Plan 9 terminals to function without a Plan 9 cpu server performing authentication. For more details, see (Vadim Antonov) has provided some information on converting terminals into multi-user hybrid cpu servers and terminals. For his posting to 9fans, see has ported a Linux QuickCam program into a Plan 9 driver which serves /dev/camera and /dev/focus. /dev/camera has the same format than /dev/screen so most of fb/* programs work well with it. The driver is at (Eran Gabber) has ported the FreeBSD driver for the Talisman XL MPEG-1 playback card for ISA bus to Plan 9. It displays full motion video in a VGA window and/or generates NTSC signal. In particular, MPEG decoding, picture resizing and video overlay are all done in hardware. However, it doesn't use DMA due to its complex architecture.
The driver is available from This page also points at a copyright disclaimer and installation instructions. Please read both carefully.

bischof@informatik.Uni-Osnabrueck.DE (Hans-Peter Bischof) has written spy, which receives the 9P messages from the kernel, displays them for modification and sends the resulting messages to the intended server. In the same way spy transmits the 9P replies of the server. Data spied out in this manner can be used in many different ways.
It is available from (Bodet Laurent) has modified the dossrv file server to read and write Linux ext2 partitions. You can find ext2srv at ftp:://

Contact if you'd like to test his Zip parallel port driver. It does nibble mode only so works with anything, just not quickly (reads are about 5mb a minute, writes double that).

If anyone would like their projects listed here, let me know. This should help prevent duplication of effort, and increase involvment from the 'net community. If you are looking for a list of suggested project topics, see

Subject: How can I get more detailed technical information?

The Internet site stores a collection of papers about the system in the plan9 directory; they are available for anonymous FTP. For a hypertext interface to these papers, see For the manual pages, see

Subject: Can I emulate Plan 9 under Unix?

Several Plan 9 inspired applications are available for Unix systems.

The sam editor is available from

There is also a Windows 95/NT version of Sam, currently distributed in binary form only, available from Comments and bug reports can be sent to

A free re-implementation of the rc shell is available from

Wily is an acme lookalike by Gary Capell, See

9wm is David Hogan's lightweight X window manager in the style of . It is available from Comments to

9term is an 8½ terminal emulator by Matty Farrow,, available from In the same directory, you'll find a collection of Unicode fonts that can be used with 9term, sam and wily.

9menu is a simple program by Arnold Robbins,, that allows you to create X menus from the shell, where each menu item will run a command. 9menu is intended for use with 9wm, but can be used with any other window manager. It is available from

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