- This article is about Free Software as defined by the Free Software Foundation. For software available
free of charge, see Freeware.
Free Software is software which, once obtained, can be used, copied,
studied, modified and redistributed. It is often made available online without charge or offline for the cost of distribution;
however, this is not required, and software can be "free as in free speech" and sold for profit. Similarly, freeware is sometimes published with source code; however, the software is not free in the
same sense as free software unless the rights to modify and redistribute modified versions of the program are guaranteed.
History
In the 1960s and 1970s, software was not
considered to be a product but rather an addon the mainframe vendors gave to their customers to use the computers at all. In that
culture, programmers and developers frequently shared their software freely among each other. This was especially common with
some of the large users groups, such as DECUS,
the DEC (Digital Equipment Corporation)
Users Group. In the late 1970s, companies started routinely imposing restrictions on users with the use of license
agreements.
In 1984, Richard Stallman
started working on the GNU project, founding the Free Software Foundation (FSF) one year later [1] (http://www.gnu.org/fsf/fsf.html). He introduced a definition for "free software" and the
concept of "copyleft", which he specifically devised to give users freedom and to
restrain the possibilities for appropriation [2] (http://cisn.metu.edu.tr/2002-6/free.php).
According to that definition, software is "free" if it grants:
- the freedom to run the program for any purpose (called "freedom 0")
- the freedom to study and modify the program ("freedom 1")
- the freedom to copy the program so you can help your neighbor ("freedom 2")
- the freedom to improve the program, and release your improvements to the public, so that the whole community benefits
("freedom 3")
Note that freedoms 1 and 3 are interpreted as requiring access to the source
code. It is possible to reverse-engineer, study, and modify software without source code, but this can be extremely difficult
and is highly ineffective compared to working directly with annotated source code.
A list of compliant licenses is available from FSF's web site (see below). The term "proprietary software" is used for software distributed under more restrictive licenses which do not grant these freedoms. Copyright law reserves most rights of modification, duplication and redistribution for the copyright owner;
software released under a free software license specifically rescinds most of these reserved rights.
The FSF definition of free software does not touch on the issue of price; a commonly used slogan is "free as in speech, not as
in beer", and it is common to see CDs of free software such as Linux distributions for sale. However, in this situation the buyer of
the CD would have the right to copy and redistribute it. Free beer software can include restrictions that do not conform
to the FSF definition — for example, gratis software may not include source code, may actively prohibit redistributors from
charging a fee, etc.
To avoid confusion, some people use the words "libre" and "gratis" to avoid the ambiguity of the English word "free". However,
these alternative terms are still used mostly within the free software movement and are only slowly spreading to the outside world.
Others advocate the term open source software. However,
according to the FSF, the Open Source movement is philosophically distinct from the free software movement. See the discussion
below (Comparison with Open Source
software).
There are several variations on free software in the FSF sense, for example:
- The freedoms defined by the FSF are protected through copyleft licenses, the
most prominent of which is the GNU General Public
License. The author retains copyright, and permits redistribution and modification under terms designed to ensure that all
modified versions of the software remain under copyleft terms.
- Public domain software, in which the author has abandoned the
copyright. Public-domain software, since it is not protected by copyright at all, may be freely incorporated into closed,
proprietary works as well as free ones.
- BSD-style licenses, so called because they are applied to much of the
software distributed with the BSD
operating systems. The author under such licenses retains copyright protection solely to disclaim warranty and to require proper
attribution of modified works, but permits redistribution and modification, even in proprietary works.
Note that the original copyright owner of copyleft-licensed software can also make a modified version under their original
copyright, and sell it under any license they like, in addition to distributing the original version as free software. This
technique has been used as a business model by a number of free software companies; this does not restrict any of the
rights granted to the users of the copyleft version.
Examples and evolution
A large and increasing amount of software is made available under free software licenses; observers of this trend (and
adherents) often refer to this phenomenon as the free
software movement. Notable free software projects include the Linux and BSD operating system kernels, the GCC compilers, GDB
debugger and C libraries, the BIND name server, the Sendmail mail transport server, the Apache web server, the MySQL
and PostgreSQL relational database systems, the Perl, Python, Tcl and
PHP programming languages, the X Window System, the GNOME and
KDE desktop environments, the OpenOffice.org office suite, the Mozilla web browser, the
Samba file server system, and the GIMP graphics editor.
Like all free software, these projects distribute their programs under licenses that grant users all the freedoms discussed
above, but because of technicalities in the licenses, combining programs by mixing source code or directly linking binaries may
be problematic unless both applications are under mutually compatible licenses. When programs are not directly linked together
into a single program, these problems do not exist. Much free software can run on non-free platforms such as Microsoft Windows, and non-free software can be run on free platforms,
although purists prefer to use all-free software running on a free platform such as Linux.
Free software packages constitute a software ecosystem where
different pieces of software can provide services to one another, leading to co-evolution of features: in one simple example, the
Python programming language provides support for the HTTP protocol, and the Apache web
server that provides the HTTP protocol can call the Python programming language to serve dynamic content.
The Debian Project, which produces an operating system entirely composed of free software, created a set of guidelines that are used to evaluate
the compatibility of a license with Debian's free-ness goal. The Debian Free Software Guidelines are used to delineate the free from non-free
software. Debian had by 2003 collected over seven and a half thousand software packages compliant with the above guidelines.
Debian developers also argue that the same principles should apply not only to programs, but to software documentation as well. Many documents written by the
Linux Documentation Project, and many
documents licensed under the GNU Free
Documentation License (the documents with invariant sections), do not comply with all of the above guidelines.
Comparison with Open Source software
While on a practical level Open Source Software and Free Software share the same licenses, according to the FSF, the Open Source movement is philosophically distinct from the free software movement. It
began in 1998 with a group of people, notably Eric S. Raymond and
Bruce Perens, who formed the Open Source Initiative (OSI). They sought to (1) bring a higher profile to the practical benefits of
sharing software source code, and (2) to interest major software houses and other high-tech industry companies in the concept.
These advocates see the term open source as avoiding the ambiguity of the English word "free" in free software. The
term "open source" was coined by Christine Peterson of the Foresight Institute think tank. It was attempted to register this as a trade mark for Free Software products, that attempt failed. Years later, the OSI finally obtained the
trade mark on "OSI Certified".
Many people recognize a qualitative benefit to the software development process when a program's source code can be used,
modified and redistributed by developers. (See also The Cathedral and the Bazaar.) The free software movement places primary emphasis on the moral
or ethical aspects of software, seeing technical excellence as a desirable by-product of its ethical standard. The Open Source
movement sees technical excellence as the primary goal, regarding source code sharing as a means to an end. As such, the FSF
distances itself both from the Open Source movement and from the term "Open Source".
Since the OSI only approves free software licenses as complying with the OSD, most people interpret it as a distribution
scheme, and freely interchange "open source" with "free software". Even though there are important philosophical differences
between the two terms, particularly in terms of the motivations for developing and using such software, they seldom make any
impact in the collaboration process.
While the term "Open Source" removes the ambiguity of Freedom versus Price, it introduces another: between programs that meet
the Open Source Definition, giving users the freedom to improve upon them, and programs that simply have source available,
possibly with heavy restrictions on the use of that source. Uninformed people might assume that any software that has source
available is "open source" because they can tinker with it themselves. However, much of this software does not give its users the
freedom to distribute their modifications, restricts commercial usage, or otherwise restricts users' rights. This is the case
with Microsoft's "shared source" initiative, and to a lesser extent with
the "licence-free" software of Daniel J. Bernstein.
Political significance
Once a free software product has started to circulate, it soon becomes available at little or no cost. At the same time, its
utility does not decrease. This means that free software can be characterized as a pure public good rather than a private good.
Since free software allows free use, modification, and distribution, it often finds a home in third world countries for whom the cost of proprietary software is sometimes prohibitive. It is also
easily modified locally, so translation efforts into languages which are not necessarily commercially profitable are also
feasible. See also internationalization.
Most free software is produced by international teams cooperating through free association. Teams typically are composed of
individuals with a wide variety of motivations. There are many stances about the relation of free software to the current,
capitalist economic system:
- Some consider free software to be a competitor to capitalism.
- Some consider free software to be another form of competition within free
markets, and that copyright is a governmental restriction on the market.
- Some compare free software to a gift economy, where a person's worth is
based on what they give away
- Groups like Oekonux and Hipatia
consider that everything could be produced in this manner and that this model of production isn't limited to superseding the
proprietary model of software development. Cooperation based on free association can be and is used for other purposes (such as
writing encyclopedias and give-away shops).
Relative security
There is a controversy about the relative security of free
software vs. proprietary software (one of the major issue being security through obscurity). A commonly used method to determine the relative security of the
products is to determine how many unpatched security flaws are in each of the products involved. It is generally advised by users
of this method that when a product provides no way to patch known security flaws, don't use it at least until the fix is
available.
As of early December, 2004 the security site Secunia counts zero security flaws unpatched (not yet fixed) for the most commonly used free software products for
internet browsing, office productivity, and e-mail - Mozilla Firefox,
OpenOffice.org and Mozilla Thunderbird, as compared to several security flaws not yet fixed for each of the three main
proprietary (Microsoft-made) equivalent software products
- Internet Explorer, Microsoft Office and Outlook Express.
External links and references
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