2 Preface to the Third (2000) Edition
4 A great deal has happened to Plan 9 in the five years since its last release.
5 Although much of the system will seem familiar, hardly any aspect
7 The kernel has been heavily reworked;
8 the graphical environment completely rewritten;
9 many commands added, deleted, or replaced;
10 and the libraries greatly expanded.
11 Underneath, though, the same approach to computing remains:
12 a distributed system that uses file-like naming to access and
13 control resources both local and remote.
15 Some of the changes are sweeping:
17 Alef is gone, a casualty of the cost of maintaining multiple languages, compilers,
18 and libraries in a diverse world,
19 but its model for processes, tasks, and communication lives on
20 in a new thread library for C.
22 Support for color displays is much more general, building on a new
23 alpha-blending graphical operator called
27 Plan 9 screens are now, discreetly, colorful.
29 A new mechanism called plumbing connects applications together
30 in a variety of ways, most obviously in the support of multimedia.
32 The interfaces to the panoply of rotating storage devices have been
34 while providing better support for having Plan 9 coexist with other
35 operating systems on a single disk.
37 Perhaps most important, this release of the system is being done under
38 an open source agreement, providing cost-free source-level access to the
41 Plan 9 continues to be the work of many people.
42 Besides those mentioned in the old preface,
43 these people deserve particular note:
44 Russ Cox did much of the work updating the graphics
45 and creating the new disk and bootstrap model
46 as well as providing a number of new commands;
47 David Hogan ported Plan 9 to the Dec Alpha;
49 Sape Mullender wrote the new thread library.
51 Other new contributors include
61 Computing Science Research Center