[ previous ] [ Contents ] [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] [ 7 ] [ 8 ] [ 9 ] [ 10 ] [ 11 ] [ 12 ] [ 13 ] [ 14 ] [ 15 ] [ 16 ] [ 17 ] [ 18 ] [ A ] [ B ] [ C ] [ D ] [ next ]

Debian Tutorial (Obsolete Documentation)
Appendix D - Miscellaneous

This chapter contains interesting information that didn't fit in the rest of the manual, such as historical notes. It may be moved to another manual in the future, or made into a coherent chapter.

D.1 Unix History

In 1969, Bell Telephone Laboratories (Bell Labs, a division of AT& T) was working with General Electric and Project MAC of MIT to write an operating system called Multics. To make a long story slightly shorter, Bell Labs decided the project wasn't going anywhere and broke out of the group. This left Bell Labs without a good operating system.

Ken Thompson and Dennis Ritchie decided to sketch out an operating system that would meet their needs. Bell Labs had an unused PDP-7 computer that Thompson wanted to put to use, so he implemented the system they had designed on that machine. As a pun on Multics, Brian Kernighan, another Bell Labs researcher, gave the system the name Unix. The group was able to get funding to buy a better computer, a PDP-11, by proposing a plan to write a word processing system. Rather than write the word processor from scratch, they made it an application that ran under Unix, which they ported to the PDP-11.

Later, Dennis Ritchie invented the "C" programming language. In 1973, Unix was rewritten in C instead of the original assembly language.[21] In 1977, Unix was moved to a new machine through a process called porting away from the PDP machines it had run on previously. This was aided by the fact Unix was written in C since much of the code could simply be recompiled and didn't have to be rewritten.

In the late 1970's, AT& T was forbidden from competing in the computing industry, so it licensed Unix to various colleges and universities very cheaply. It was slow to catch on outside of academic institutions but was eventually popular with businesses as well. The Unix of today is different from the Unix of 1970. It has two major variations: System V, from Unix System Laboratories (USL), a subsidiary of SCO[22], and the Berkeley Software Distribution (BSD). The USL version is now up to its forth release, or SVR4[23], while BSD's latest version is 4.4. However, there are many different versions of Unix besides these two. Most proprietary versions of Unix derive from one of the two groupings. The versions of Unix that are actually used usually incorporate features from both variations.

Current proprietary versions of Unix for Intel PCs cost between $500 and $2000, with the exception of Solaris x86 which has been crushed by free Unix clones and forced to lower prices.

D.2 GNU/Linux History

Debian traces its roots to the founding of the GNU project in 1984 by Richard M. Stallman. GNU (GNU's Not Unix) is a project of the Free Software Foundation; their goal was and is to replace the Unix operating system with free software. They had written almost an entire operating system by the early 1990s, but the kernel was missing. Fortunately, Linux appeared to fill this gap.

The primary author of the Linux kernel is Linus Torvalds. Since his original versions, it has been improved by countless numbers of people around the world. It is a clone, written entirely from scratch, of the Unix operating system. Neither USL, nor the University of California, Berkeley, were involved in writing Linux. One of the more interesting facts about Linux is that development occurs simultaneously around the world. People from Australia to Finland contributed to Linux and will hopefully continue to do so.

Linux began with a project to explore the 386 chip. One of Linus's earlier projects was a program that would switch between printing AAAA and BBBB. This later evolved into Linux.

Linux has been copyrighted under the terms of the GNU General Public License (GPL). This is a license written by the Free Software Foundation (FSF) that is designed to keep software free. In brief, it says that although you can charge as much as you'd like for a copy, you can't prevent the person you sold it to from selling it, giving it away, or modifying it. It also means that the source code[24] must also be available. This is useful for programmers. Anybody can modify Linux and even distribute their modifications, provided that they keep the code under the same copyright --- the GPL.

Debian is called GNU/Linux because it is a product of two massive efforts, the Linux kernel and the GNU project. Still, focusing on only these two contributions leaves out tens of thousands of contributors. It's impossible to keep track of everyone who's made Debian what it is today.

The following two lists, of leaders and release milestones, are copyrighted by Software in the Public Interest and may be redistributed but not modified.

Debian has had several leaders since its beginnings in 1993.

Here are a few of the major Debian release milestones:

D.3 The Linux kernel's version numbering

The first number in Linux's version number indicates truly huge revisions. These change very slowly: right now version 2 is the latest. The second number indicates less major revisions. Even second numbers signify more stable, dependable versions of Linux while odd numbers are developer's versions that are more prone to bugs. The final version number is the minor release number---every time a new version is released that may just fix small problems or add minor features, that number is increased by one. Right now the stable kernel is 2.0, and the developer's kernel is 2.1. When 2.1 is ready, it will become stable kernel 2.2. The latest version of the stable kernel is currently 2.0.35, though that may well change by the time you read this. The 2.2 stable release is expected soon.

[ previous ] [ Contents ] [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] [ 7 ] [ 8 ] [ 9 ] [ 10 ] [ 11 ] [ 12 ] [ 13 ] [ 14 ] [ 15 ] [ 16 ] [ 17 ] [ 18 ] [ A ] [ B ] [ C ] [ D ] [ next ]

Debian Tutorial (Obsolete Documentation)

29 Dezember 2009

Havoc Pennington hp@debian.org