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6 <H1>Preface to the Third (2000) Edition
9 A great deal has happened to Plan 9 in the five years since its last release.
10 Although much of the system will seem familiar, hardly any aspect
12 The kernel has been heavily reworked;
13 the graphical environment completely rewritten;
14 many commands added, deleted, or replaced;
15 and the libraries greatly expanded.
16 Underneath, though, the same approach to computing remains:
17 a distributed system that uses file-like naming to access and
18 control resources both local and remote.
20 Some of the changes are sweeping:
23 Alef is gone, a casualty of the cost of maintaining multiple languages, compilers,
24 and libraries in a diverse world,
25 but its model for processes, tasks, and communication lives on
26 in a new thread library for C.
28 Support for color displays is much more general, building on a new
29 alpha-blending graphical operator called
33 Plan 9 screens are now, discreetly, colorful.
35 A new mechanism called plumbing connects applications together
36 in a variety of ways, most obviously in the support of multimedia.
38 The interfaces to the panoply of rotating storage devices have been
40 while providing better support for having Plan 9 coexist with other
41 operating systems on a single disk.
43 Perhaps most important, this release of the system is being done under
44 an open source agreement, providing cost-free source-level access to the
48 Plan 9 continues to be the work of many people.
49 Besides those mentioned in the old preface,
50 these people deserve particular note:
51 Russ Cox did much of the work updating the graphics
52 and creating the new disk and bootstrap model
53 as well as providing a number of new commands;
54 David Hogan ported Plan 9 to the Dec Alpha;
56 Sape Mullender wrote the new thread library.
58 Other new contributors include
75 Computing Science Research Center
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83 Copyright</A> © 2000 Lucent Technologies Inc. All rights reserved.