Free software,
software libre or
libre software is
software
that can be used, studied, and modified without restriction, and
which can be copied and redistributed in modified or unmodified
form either without restriction, or with minimal restrictions only
to ensure that further recipients can also do these things and that
manufacturers of consumer-facing hardware allow user modifications
to their hardware. Free software is available gratis (free of
charge) in most cases.
In practice, for software to be distributed as free software, the
human-readable form of the program (the
source code) must be made available to the
recipient along with a notice granting the above permissions. Such
a notice either is a "
free
software license", or a notice that the source code is released
into the
public domain.
The
free software movement
was conceived in 1983 by
Richard
Stallman to satisfy the need for and to give the benefit of
"software freedom" to computer users. The
Free Software Foundation was
founded in 1985 to provide the organizational structure which
Stallman correctly foresaw would be necessary to advance his Free
Software ideas.
From 1998 onward,
alternative terms for free
software came into use. The most common are "software libre",
"
free and open source
software" ("FOSS") and "free, libre and open source software"
("FLOSS"). The "Software Freedom Law Center" was founded in 2005 to
protect and advance FLOSS. The antonym of free software is
"
proprietary software" or
"non-free software". Commercial software may be either free
software or proprietary software, contrary to a popular
misconception that "commercial software" is a synonym for
"proprietary software". (An example of commercial free software is
Red Hat Linux.)
Free software, which may or may not be distributed free of charge,
is distinct from "
freeware" which, by
definition, does not require payment for use. The authors or
copyright holders of freeware may retain all rights to the
software; it is not necessarily permissible to
reverse engineer, modify, or
redistribute freeware.
Since free software may be freely redistributed it is generally
available at little or no cost. Free software business models are
usually based on adding value such as applications, support,
training, customization, integration, or certification. At the same
time, some business models which work with
proprietary software are not compatible
with free software, such as those that depend on a user paying for
a license in order to lawfully use a software product.
History
In the 1950s, 1960s, and 1970s, it was normal for computer users to
have the freedoms that are provided by free software.
Software was commonly shared by individuals who
used computers and by hardware manufacturers who were glad that
people were making software that made their hardware useful.
Organizations of users and suppliers were formed to facilitate the
exchange of software, see, for example,
SHARE. By the late 1960s change was
inevitable: software costs were dramatically increasing, a growing
software industry was competing with the hardware manufacturer's
bundled software products (free in that the cost was included in
the hardware cost), leased machines required software support while
providing no revenue for software, and some customers able to
better meet their own needs did not want the costs of "free"
software bundled with hardware product costs. In
United States
vs. IBM, filed January 17, 1969, the
government charged that bundled software was anticompetitive. While
some software might always be free, there would be a growing amount
of software that was for sale only. In the 1970s and early 1980s,
the
software industry began using
technical measures (such as only distributing
binary copies of
computer programs) to prevent
computer users from being able to study and
modify software. In 1980
copyright law was
extended to computer programs.
In 1983,
Richard Stallman, longtime
member of the
hacker
community at the
MIT Artificial
Intelligence Laboratory, announced the
GNU project, saying that he had become
frustrated with the effects of the change in culture of the
computer industry and its users. Software development for the
GNU operating system began in
January 1984, and the
Free
Software Foundation (FSF) was founded in October 1985. He
developed a free software definition and the concept of "
copyleft", designed to ensure software freedom for
all.
The economic viability of free software has been recognised by
large corporations such as
IBM,
Red Hat, and
Sun
Microsystems. Many companies whose core business is not in the
IT sector choose free software for their Internet information and
sales sites, due to the lower initial capital investment and
ability to freely customize the application packages. Also, some
non-software industries are beginning to use techniques similar to
those used in free software development for their research and
development process; scientists, for example, are looking towards
more open development processes, and hardware such as microchips
are beginning to be developed with specifications released under
copyleft licenses (see the
OpenCores project, for instance).
Creative Commons and the
free culture movement have also been
largely influenced by the free software movement.
Naming
The FSF recommends using the term "free software" rather than
"
open source software" because,
they state in a paper on Free Software philosophy, the latter term
and the associated marketing campaign focuses on the technical
issues of software development, avoiding the issue of user
freedoms. "
Libre" is used to avoid the
ambiguity of the word "free".
Definition
The first formal definition of free software was published by FSF
in February 1986. That definition, written by Richard Stallman, is
still maintained today and states that software is free software if
people who receive a copy of the software have the following four
freedoms:
- Freedom 0: The freedom to run the program for any purpose.
- Freedom 1: The freedom to study how the program works, and
change it to make it do what you wish.
- Freedom 2: The freedom to redistribute copies so you can help
your neighbor.
- Freedom 3: The freedom to improve the program, and release your
improvements (and modified versions in general) to the public, so
that the whole community benefits.
Freedoms 1 and 3 require
source code to
be available because studying and modifying software without its
source code is highly impractical.
Thus, free software means that
computer
users have the freedom to cooperate with whom they choose, and
to control the software they use. To summarize this into a remark
distinguishing
libre
(freedom) software from
gratis (zero price) software,
Richard Stallman said: "Free
software is a matter of liberty, not price. To understand the
concept, you should think of 'free' as in '
free speech', not as in '
free beer .
In the late 90s, other groups published their own definitions which
describe an almost identical set of software. The most notable are
Debian Free Software
Guidelines published in 1997, and the
Open Source Definition, published in
1998.
The BSD-based operating systems, such as
FreeBSD,
OpenBSD, and
NetBSD, do not have their own formal
definitions of free software. Users of these systems generally find
the same set of software to be acceptable, but sometimes see
copyleft as restrictive. They generally advocate
permissive free software
licenses, which allow others to make software based on their
source code, and then release the modified result as proprietary
software. Their view is that this permissive approach is more free.
The
Kerberos,
X.org, and
Apache
software licenses are substantially similar in intent and
implementation.
All of these software packages originated in
academic institutions interested in wide technology transfer
(University of California,
MIT
, and UIUC
).
Examples of free software
The
Free Software Directory
maintains a large database of free software packages. Some of the
best-known examples include the
Linux
Kernel, the
BSD
and
GNU/Linux operating systems, the
GNU Compiler Collection and
C library; the
MySQL
relational database; the
Apache
web server; and the
Sendmail mail transport
agent. Other influential examples include the
emacs text editor; the
GIMP raster
drawing and image editor; the
X Window
System graphical-display system; the
OpenOffice.org office suite; and the
TeX and
LaTeX typesetting
systems.
Free software licenses
All free software licenses must grant people all the freedoms
discussed above. However, unless the applications' licenses are
compatible, combining programs by mixing source code or directly
linking binaries is problematic, because of license technicalities.
Programs indirectly connected together may avoid this
problem.
The majority of free software uses a small set of licenses. The
most popular of these licenses are:
The Free Software Foundation and the Open Source Initiative both
publish lists of licenses that they find to comply with their own
definitions of free software and open-source software respectively.
The FSF list is not prescriptive: free licensees can exist which
the FSF has not heard about, or considered important enough to
write about. So it's possible for a license to be free and not in
the FSF list. However, the OSI list is prescriptive: they only list
licenses that have been submitted, considered and approved. This
formal process of approval is what defines a license as Open
Source. Thus, it's not possible for a license to be Open Source and
not on the OSI approved list.
Apart from these two organizations, the
Debian project is seen by some to provide useful
advice on whether particular licenses comply with their
Debian Free Software
Guidelines. Debian doesn't publish a list of
approved
licenses, so its judgments have to be tracked by checking what
software they have allowed into their software archives. That is
summarized at the Debian web site.
It is rare that a license is announced as being in-compliance by
either FSF or OSI guidelines and not vice versa (the
Netscape Public License used for
early versions of Mozilla being an exception, as well as the
NASA Open Source
Agreement).
Permissive and copyleft licenses
The FSF categorizes licenses in the following ways:
- Public domain software – the
copyright has expired, the work was not copyrighted or the author
has released the software onto the public domain. Since
public-domain software lacks copyright protection, it may be freely
incorporated into any work, whether proprietary or free.
- Permissive
licenses, also called BSD-style because they are applied to
much of the software distributed with the BSD operating systems. The
author retains copyright solely to disclaim warranty and require
proper attribution of modified works, and permits redistribution
and any modification, even proprietary ones.
- Copyleft licenses, the GNU General Public License being
the most prominent. The author retains copyright and permits
redistribution and modification provided all such redistribution is
licensed under the same license. Additions and modifications by
others must also be licensed under the same "copyleft" license
whenever they are distributed with part of the original licensed
product.
Security and reliability
There is debate over the
security
of free software in comparison to proprietary software, with a
major issue being
security
through obscurity. A popular quantitative test in computer
security is to use relative counting of known unpatched security
flaws. Generally, users of this method advise avoiding products
which lack fixes for known security flaws, at least until a fix is
available.
Free software advocates say that this method is biased by counting
more vulnerabilities for the free software, since its source code
is accessible and its community is more forthcoming about what
problems exist, and proprietary software can have undisclosed flaws
discoverable by or known to malicious users. As users can analyse
and trace the source code, many more people with no commercial
constraints can inspect the code and find bugs and loopholes than a
corporation would find practicable. User access to the source code
makes deploying free software with undesirable hidden
spyware functionality far more difficult than for
proprietary software.
Commercial viability and adoption
Free software played a part in the development of the Internet, the
World Wide Web and the infrastructure of
dot-com companies. Free software allows
users to cooperate in enhancing and refining the programs they use;
free software is a
pure public good
rather than a
private good. Companies
that contribute to free software can increase commercial
innovation amidst the void of
patent cross licensing
lawsuits. (See
mpeg2 patent
holders.)
Under the free software business model, free software vendors may
charge a fee for distribution and offer pay support and software
customization services. Proprietary software uses a different
business model, where a customer of the proprietary software pays a
fee for a license to use the software. This license may grant the
customer the ability to configure some or no parts of the software
themselves. Often some level of support is included in the purchase
of proprietary software, but additional support services
(especially for enterprise applications) are usually available for
an additional fee. Some proprietary software vendors will also
customize software for a fee.
Free software is generally available at no cost and can result in
permanently lower costs compared to
proprietary software. With free
software, businesses can fit software to their specific needs by
changing the software themselves or by hiring programmers to modify
it for them. Free software often has no warranty, and more
importantly, generally does not assign legal liability to anyone.
However, warranties are permitted between any two parties upon the
condition of the software and its usage. Such an agreement is made
separately from the free software license.
A report by Standish Group says that adoption of
open source has caused a drop in revenue to the
proprietary software industry
by about $60 billion per year.
Controversies
Binary blobs
In 2006,
OpenBSD started the first campaign
against the use of
binary blobs, in
kernels. Blobs are usually
freely distributable
device drivers
for hardware from vendors that do not reveal driver source code to
users or developers. This restricts the users' freedom to
effectively modify the software and distribute modified versions.
Also, since the blobs are undocumented and may have
bugs, they pose a security risk to any
operating system whose kernel includes
them. The proclaimed aim of the campaign against blobs is to
collect hardware documentation that allows developers to write free
software drivers for that hardware, ultimately enabling all free
operating systems to become or remain blob-free.
The issue of binary blobs in the
Linux
kernel and other device drivers motivated some developers in
Ireland to launch
gNewSense, a GNU/Linux
distribution with all the binary blobs removed. The project
received support from the
Free
Software Foundation.
BitKeeper
Larry McVoy invited high-profile free
software projects to use his proprietary
versioning system,
BitKeeper, free of charge, in order to attract
paying users. In 2002, Linux coordinator
Linus Torvalds decided to use BitKeeper to
develop the
Linux kernel, a free
software project, claiming no free software alternative met his
needs. This controversial decision drew criticism from several
sources, including the Free Software Foundation's founder Richard
Stallman.
Following the apparent
reverse
engineering of BitKeeper's protocols, McVoy withdrew permission
for gratis use by free software projects, leading the Linux kernel
community to develop a free software replacement called
Git.
Patent deals
In November 2006, the
Microsoft and
Novell software corporations announced a
controversial partnership involving, among other things, patent
protection for some customers of Novell under certain
conditions.
See also
References
- FSF: The four freedoms
- http://standishgroup.com/newsroom/open_source.php
- GNU/Linux distributions we know of which consist
entirely of free software, and whose main distribution sites
distribute only free software.
External links
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