9P

9P (or the Plan 9 Filesystem Protocol or Styx), is a network protocol developed for the Plan 9 from Bell Labs distributed operating systemas the means of connecting the components of a Plan 9 system.Files are key objects in Plan 9. They represent windows, network connections, processes, and almost anything else available in the operating system.9P encourages caching and also serving of synthetic files (e.g. /proc to represent processes), unlike NFS.

9P was revised for the 4th edition of Plan 9 under the name 9P2000 that contained various fundamental improvements. The latest version of Inferno also uses 9P2000. The Inferno file protocol was originally called Styx, but technically it has always been a variant of 9P.

Another revision called 9p2000.u which is modified to better support UNIX environments also exists, see [http://v9fs.sourceforge.net/rfc/9p2000.u.html v9fs 9p2000.u] .

There is a server implementation of 9P for Unix called u9fs included in the Plan 9 distribution, and a kernel client driver for Linux as part of the v9fs project. 9P (and derivatives) have also found application in embedded environments, such as the [http://www.vitanuova.com/inferno/rcx_paper.html Styx on a Brick project] .

9P server applications

Many of Plan 9's applications take the form of 9P servers; some particularly noteworthy examples:
* acme: a user interface for programmers
* rio: the Plan 9 window manager.
* plumber: interprocess communication
* wikifs: a wiki

See also

* v9fs - u9fs: 9P implementation for Unix-like operating systems
* IL Protocol - Transport protocol that was designed for 9P in local area networks.
* distributed file system

External links

* [http://9p.cat-v.org/ 9P Resources] page at cat-v.org

Documentation
* [http://www.cs.bell-labs.com/magic/man2html/5/0intro 9P Manual]
* [http://doc.cat-v.org/inferno/4th_edition/styx The Styx Architecture for Distributed Systems] by Rob Pike and Dennis Ritchie
* [http://www.cs.bell-labs.com/sys/doc/net.html The Organization of Networks in Plan 9] by Dave Presotto and Phil WinterbottomImplementations
* [http://lava.net/~newsham/plan9/ 9P server and client] implementations in Python
* [http://jstyx.sf.net 9P server and client] implementations in Java
* [http://code.google.com/p/styx-n-9p/ styx-n-9p] Vita Nuova-developed Java client supporting Inferno authentication protocol
* [http://home.gna.org/rubyixp/ Ruby-IXP] 9P client implemented in Ruby for wmii
* [http://rstyx.rubyforge.org/ RStyx] 9P client and server implemented in Ruby supporting Inferno authentication protocol
* [http://wiki.tcl.tk/15632 9P client] implemenations in Tcl
* [http://www.suckless.org/wiki/libs 9P server and client] implementation in C under the BSD license (part of the wmii project)
* [http://common-lisp.net/project/ninep/ 9P client] implementation in Common Lisp
* [http://swtch.com/plan9port/man/man3/9pclient.html 9pclient library] - A 9P library in C (part of the Plan 9 from User Space project)
* [http://www.vitanuova.com/inferno/net_download4T.html Styx server and client] implementations in Limbo (part of the Inferno operating system)
* [http://code.google.com/p/limbo-machine Styx client library in JavaScript] - part of the limbo machine project