1*219b2ee8SDavid du Colombier.TL 2*219b2ee8SDavid du ColombierPreface 3*219b2ee8SDavid du Colombier.PP 4*219b2ee8SDavid du ColombierPlan 9 was born in the same lab where Unix began. 5*219b2ee8SDavid du ColombierOld Unix hands will recognize the cultural heritage in this manual, 6*219b2ee8SDavid du Colombierwhere venerable Unix commands live on, 7*219b2ee8SDavid du Colombierdescribed in the classic Unix style. Underneath, though, lies 8*219b2ee8SDavid du Colombiera new kind of system, organized around communication and 9*219b2ee8SDavid du Colombiernaming rather than files and processes. 10*219b2ee8SDavid du Colombier.PP 11*219b2ee8SDavid du ColombierIn Plan 9, distributed computing is a central premise, 12*219b2ee8SDavid du Colombiernot an evolutionary add-on. The system relies on a 13*219b2ee8SDavid du Colombieruniform protocol to refer to and communicate 14*219b2ee8SDavid du Colombierwith objects, whether they be data or processes, and whether or 15*219b2ee8SDavid du Colombiernot they live on the same machine or even similar machines. 16*219b2ee8SDavid du ColombierA single paradigm (writing to named places) unifies 17*219b2ee8SDavid du Colombierall kinds of control and interprocess signaling. 18*219b2ee8SDavid du Colombier.PP 19*219b2ee8SDavid du ColombierName spaces can be built arbitrarily. In particular all 20*219b2ee8SDavid du Colombierprograms available to a given user are customarily united 21*219b2ee8SDavid du Colombierin a single logical directory. 22*219b2ee8SDavid du ColombierTemporary files and 23*219b2ee8SDavid du Colombieruntrusted activities can be confined in isolated spaces. 24*219b2ee8SDavid du ColombierWhen a portable machine connects to the 25*219b2ee8SDavid du Colombiercentral, archival file system, the machine's local 26*219b2ee8SDavid du Colombiername space is joined smoothly to that of the archival file system. 27*219b2ee8SDavid du ColombierThe architecture affords other unusual abilities, including: 28*219b2ee8SDavid du Colombier.IP 29*219b2ee8SDavid du ColombierObjects in name spaces imported from other machines (even from 30*219b2ee8SDavid du Colombierforeign systems such as MS-DOS) are transparently accessible. 31*219b2ee8SDavid du Colombier.IP 32*219b2ee8SDavid du ColombierWindows appear in name spaces on a par with files and processes. 33*219b2ee8SDavid du Colombier.IP 34*219b2ee8SDavid du ColombierA historical file system allows one to navigate 35*219b2ee8SDavid du Colombierthe archival file system in time as well as in space; 36*219b2ee8SDavid du Colombierbackup files are always at hand. 37*219b2ee8SDavid du Colombier.IP 38*219b2ee8SDavid du ColombierA debugger can handle simultaneously active processes 39*219b2ee8SDavid du Colombieron disparate kinds of hardware. 40*219b2ee8SDavid du Colombier.PP 41*219b2ee8SDavid du ColombierThe character set of Plan 9 is Unicode, which 42*219b2ee8SDavid du Colombiercovers most of the world's major scripts. 43*219b2ee8SDavid du ColombierThe system has its own programming languages: 44*219b2ee8SDavid du Colombiera dialect of C with simple inheritance, a simplified shell, 45*219b2ee8SDavid du Colombierand a CSP-like concurrent language, Alef. 46*219b2ee8SDavid du ColombierAn ANSI-POSIX emulator (APE) admits unreconstructed Unix code. 47*219b2ee8SDavid du Colombier.PP 48*219b2ee8SDavid du ColombierPlan 9 is the work of many people. 49*219b2ee8SDavid du ColombierThe protocol was begun by Ken Thompson; naming 50*219b2ee8SDavid du Colombierwas integrated by Rob Pike and networking by Dave Presotto. 51*219b2ee8SDavid du ColombierPhil Winterbottom simplified the management of name spaces 52*219b2ee8SDavid du Colombierand re-engineered the system. 53*219b2ee8SDavid du ColombierThey were joined by Tom Killian, Jim McKie, and Howard Trickey in 54*219b2ee8SDavid du Colombierbringing the system up on various machines and making 55*219b2ee8SDavid du Colombierdevice drivers. 56*219b2ee8SDavid du ColombierThompson made the C compiler; 57*219b2ee8SDavid du ColombierPike, window systems; 58*219b2ee8SDavid du ColombierTom Duff, the shell and raster graphics; 59*219b2ee8SDavid du ColombierWinterbottom, Alef; 60*219b2ee8SDavid du ColombierTrickey, Duff, and Andrew Hume, APE. 61*219b2ee8SDavid du ColombierBob Flandrena ported a myriad of 62*219b2ee8SDavid du Colombierprograms to Plan 9. 63*219b2ee8SDavid du ColombierOther contributors include 64*219b2ee8SDavid du ColombierAlan Berenbaum, 65*219b2ee8SDavid du ColombierLorinda Cherry, 66*219b2ee8SDavid du ColombierBill Cheswick, 67*219b2ee8SDavid du ColombierSean Dorward, 68*219b2ee8SDavid du ColombierDavid Gay, 69*219b2ee8SDavid du ColombierPaul Glick, 70*219b2ee8SDavid du ColombierEric Grosse, 71*219b2ee8SDavid du ColombierJohn Hobby, 72*219b2ee8SDavid du ColombierGerard Holzmann, 73*219b2ee8SDavid du ColombierBrian Kernighan, 74*219b2ee8SDavid du ColombierBart Locanthi, 75*219b2ee8SDavid du ColombierDoug McIlroy, 76*219b2ee8SDavid du ColombierJudy Paone, 77*219b2ee8SDavid du ColombierSean Quinlan, 78*219b2ee8SDavid du ColombierBob Restrick, 79*219b2ee8SDavid du ColombierDennis Ritchie, 80*219b2ee8SDavid du ColombierBjarne Stroustrup, 81*219b2ee8SDavid du Colombierand 82*219b2ee8SDavid du ColombierCliff Young. 83*219b2ee8SDavid du Colombier.PP 84*219b2ee8SDavid du ColombierPlan 9 is made available as is, without formal support, but 85*219b2ee8SDavid du Colombiersubstantial comments or contributions may be communicated to 86*219b2ee8SDavid du Colombierthe authors. 87*219b2ee8SDavid du Colombier.sp 88*219b2ee8SDavid du Colombier.in 4i 89*219b2ee8SDavid du ColombierDoug McIlroy 90*219b2ee8SDavid du Colombier.br 91*219b2ee8SDavid du ColombierMarch, 1995 92