Information Technology Reference
In-Depth Information
In order to be fully functional, a modern operating system must include text editors,
command processors, assemblers, compilers, debuggers, device drivers, mail servers,
and many other programs. During the late 1980s, Stallman and others developed most of
the necessary components. The GNU Project also benefited from open-source software
previously developed by others, notably Donald Knuth's T
E
X typesetting system (used
to typeset this topic) and MIT's X Window System. Most of the software developed as
part of the GNU Project is distributed under the GNU Public License, an example of
an open-source license. (For technical reasons some programs have been distributed as
open-source software under other licenses.)
In 1991 Linus Torvalds began work on a Unix-like kernel he named Linux. (The
kernel is the software at the very heart of an operating system.) He released version 1.0 of
the kernel in 1994. Because the other major components of a Unix-like operating system
had already been created through the GNU Project, Torvalds was able to combine all of
the software into a complete, open-source, Unix-like operating system. To the obvious
chagrin of Stallman, Linux has become the commonly accepted name for the open-
source operating system based on the Linux kernel. (Stallman urges people to refer to
the entire system as GNU/Linux [131].)
In 1998 Andrew Leonard summarized the impact of Linux this way: “Linux is subversive.
Who could have thought even five years ago that a world-class operating system could
coalesce as if by magic out of part-time hacking by several thousand developers scattered
all over the planet, connected only by the tenuous strands of the Internet?” [127].
Linux has become a viable alternative to proprietary versions of Unix. Many com-
panies adopted Linux as a way to cut costs during the recession of 2008-2009 [132]. A
survey conducted in June 2013 revealed that 95 percent of the world's 500 fastest super-
computers were running the Linux operating system [133].
The open-source movement has many detractors. They have raised the following criti-
cisms of the open-source model of software development.
First, if a particular open-source project does not attract a critical mass of develop-
ers, the overall quality of the software can be poor [126].
Second, without an “owner,” there is always the possibility that different groups of
users will independently make enhancements to a software product that are incompat-
ible with each other. The source code to a single program may fork into a multitude
of irreconcilable versions. (In reality, this possibility hasn't materialized. Code forking
would fragment the developer community, which is bad for everyone. Hence there are
incentives to keep a single version of the source code. About 99 percent of Linux distri-
butions have the same source code [126].)
Third, open-source software as a whole tends to have a relatively weak graphical
user interface, making it harder to use than commercial software products. This is one
