Free software, libre software, libreware
sometimes known as freedom-respecting software is computer
software
Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications.
The history of software is closely tied to the development of digital comput ...
distributed
under terms that allow users to run the software for any purpose as well as to study, change, distribute it and any adapted versions.
Free software is a matter of
liberty
Liberty is the state of being free within society from oppressive restrictions imposed by authority on one's way of life, behavior, or political views. The concept of liberty can vary depending on perspective and context. In the Constitutional ...
, not price; all users are legally free to do what they want with their copies of a free software (including profiting from them) regardless of how much is paid to obtain the program.
[Selling Free Software](_blank)
(GNU) Computer programs are deemed "free" if they give end-users (not just the developer) ultimate control over the software and, subsequently, over their devices.
The right to study and modify a computer program entails that the
source code
In computing, source code, or simply code or source, is a plain text computer program written in a programming language. A programmer writes the human readable source code to control the behavior of a computer.
Since a computer, at base, only ...
—the preferred format for making changes—be made available to users of that program. While this is often called "access to source code" or "public availability", the Free Software Foundation (FSF) recommends against thinking in those terms, because it might give the impression that users have an obligation (as opposed to a right) to give non-users a copy of the program.
Although the term "free software" had already been used loosely in the past and other permissive software like the
Berkeley Software Distribution
The Berkeley Software Distribution (BSD), also known as Berkeley Unix or BSD Unix, is a discontinued Unix operating system developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley, beginn ...
released in 1978 existed,
Richard Stallman
Richard Matthew Stallman ( ; born March 16, 1953), also known by his initials, rms, is an American free software movement activist and programmer. He campaigns for software to be distributed in such a manner that its users have the freedom to ...
is credited with tying it to the sense under discussion and starting the
free software movement
The free software movement is a social movement with the goal of obtaining and guaranteeing certain freedoms for user (computing), software users, namely the freedoms to run, study, modify, and share copies of software. Software which meets thes ...
in 1983, when he launched the
GNU Project
The GNU Project ( ) is a free software, mass collaboration project announced by Richard Stallman on September 27, 1983. Its goal is to give computer users freedom and control in their use of their computers and Computer hardware, computing dev ...
: a collaborative effort to create a freedom-respecting
operating system
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ...
, and to revive the spirit of cooperation once prevalent among
hackers during the early days of computing.
Context

Free software differs from:
*
proprietary software
Proprietary software is computer software, software that grants its creator, publisher, or other rightsholder or rightsholder partner a legal monopoly by modern copyright and intellectual property law to exclude the recipient from freely sharing t ...
, such as
Microsoft Office,
Windows
Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...
,
Adobe Photoshop
Adobe Photoshop is a raster graphics editor developed and published by Adobe Inc., Adobe for Microsoft Windows, Windows and macOS. It was created in 1987 by Thomas Knoll, Thomas and John Knoll. It is the most used tool for professional digital ...
,
Facebook
Facebook is a social media and social networking service owned by the American technology conglomerate Meta Platforms, Meta. Created in 2004 by Mark Zuckerberg with four other Harvard College students and roommates, Eduardo Saverin, Andre ...
or
FaceTime
FaceTime is a proprietary videotelephony product developed by Apple. FaceTime is available on supported iOS mobile devices running iOS 4 and later and Mac computers that run and later. FaceTime supports any iOS device with a forward-facin ...
. Users cannot study, change, and share their
source code
In computing, source code, or simply code or source, is a plain text computer program written in a programming language. A programmer writes the human readable source code to control the behavior of a computer.
Since a computer, at base, only ...
.
*
freeware or gratis software, which is a category of proprietary software that does not require payment for basic use.
For software under the purview of
copyright
A copyright is a type of intellectual property that gives its owner the exclusive legal right to copy, distribute, adapt, display, and perform a creative work, usually for a limited time. The creative work may be in a literary, artistic, ...
to be free, it must carry a
software license
A software license is a legal instrument governing the use or redistribution of software.
Since the 1970s, software copyright has been recognized in the United States. Despite the copyright being recognized, most companies prefer to sell lic ...
whereby the author grants users the aforementioned rights. Software that is not covered by copyright law, such as software in the
public domain
The public domain (PD) consists of all the creative work to which no Exclusive exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly Waiver, waived, or may be inapplicable. Because no one holds ...
, is free as long as the source code is also in the public domain, or otherwise available without restrictions.
Proprietary software uses restrictive software licences or
EULAs and usually does not provide users with the source code. Users are thus legally or technically prevented from
changing the software, and this results in reliance on the publisher to provide updates, help, and support. (''See also
vendor lock-in
In economics, vendor lock-in, also known as proprietary lock-in or customer lockin, makes a customer dependent on a vendor for products, unable to use another vendor without substantial switching costs.
The use of open standards and alternati ...
and
abandonware
Abandonware is a term for software, typically video games, that are no longer for sale by conventional means and are distributed by warez websites for free. The use of the "abandonware" term is controversial, as distributing out-of-print softw ...
''). Users often may not
reverse engineer, modify, or redistribute proprietary software.
Beyond copyright law, contracts and a lack of source code, there can exist additional obstacles keeping users from exercising freedom over a piece of software, such as
software patent
A software patent is a patent on a piece of software, such as a computer program, library, user interface, or algorithm. The validity of these patents can be difficult to evaluate, as software is often at once a product of engineering, something ...
s and
digital rights management
Digital rights management (DRM) is the management of legal access to digital content. Various tools or technological protection measures, such as access control technologies, can restrict the use of proprietary hardware and copyrighted works. DRM ...
(more specifically,
tivoization
Tivoization () is the practice of designing hardware that incorporates software under the terms of a copyleft software license like the GNU General Public License (GNU GPL), but uses hardware restrictions or digital rights management (DRM) to p ...
).
Free software can be a for-profit, commercial activity or not. Some free software is developed by volunteer
computer programmers while other is developed by corporations; or even by both.
Naming and differences with open source
Although both definitions refer to almost equivalent corpora of programs, the Free Software Foundation recommends using the term "free software" rather than "
open-source software
Open-source software (OSS) is Software, computer software that is released under a Open-source license, license in which the copyright holder grants users the rights to use, study, change, and Software distribution, distribute the software an ...
" (an alternative, yet similar, concept coined in 1998), because the goals and messaging are quite dissimilar. According to the Free Software Foundation, "Open source" and its associated campaign mostly focus on the technicalities of the
public development model and marketing free software to businesses, while taking the ethical issue of user rights very lightly or even antagonistically.
Stallman has also stated that considering the practical advantages of free software is like considering the practical advantages of not being handcuffed, in that it is not necessary for an individual to consider practical reasons in order to realize that being handcuffed is undesirable in itself.
The FSF also notes that "Open Source" has exactly one specific meaning in common English, namely that "you can look at the source code." It states that while the term "Free Software" can lead to two different interpretations, at least one of them is consistent with the intended meaning unlike the term "Open Source". The loan adjective "
libre" is often used to avoid the ambiguity of the word "free" in the
English language
English is a West Germanic language that developed in early medieval England and has since become a English as a lingua franca, global lingua franca. The namesake of the language is the Angles (tribe), Angles, one of the Germanic peoples th ...
, and the ambiguity with the older usage of "free software" as public-domain software.
(''See
Gratis versus libre
The adjective ''free'' in English is commonly used in one of two meanings: "at no monetary cost" (''gratis'') or "with little or no restriction" (''libre''). This ambiguity can cause issues where the distinction is important, as it often is in ...
.'')
Definition and the Four Essential Freedoms of Free Software

The first formal definition of free software was published by FSF in February 1986.
That definition, written by
Richard Stallman
Richard Matthew Stallman ( ; born March 16, 1953), also known by his initials, rms, is an American free software movement activist and programmer. He campaigns for software to be distributed in such a manner that its users have the freedom to ...
, 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.
The numbering begins with zero, not only as a spoof on the common usage of
zero-based numbering in programming languages, but also because "Freedom 0" was not initially included in the list, but later added first in the list as it was considered very important.
* Freedom 0: The freedom to use 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 and make 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
In computing, source code, or simply code or source, is a plain text computer program written in a programming language. A programmer writes the human readable source code to control the behavior of a computer.
Since a computer, at base, only ...
to be available because studying and modifying software without its source code can range from highly impractical to nearly impossible.
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, the Free Software Foundation says: "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.
(''See
Gratis versus libre
The adjective ''free'' in English is commonly used in one of two meanings: "at no monetary cost" (''gratis'') or "with little or no restriction" (''libre''). This ambiguity can cause issues where the distinction is important, as it often is in ...
.'')
In the late 1990s, other groups published their own definitions that 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
FreeBSD is a free-software Unix-like operating system descended from the Berkeley Software Distribution (BSD). The first version was released in 1993 developed from 386BSD, one of the first fully functional and free Unix clones on affordable ...
,
OpenBSD
OpenBSD is a security-focused operating system, security-focused, free software, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by fork (software development), forking NetBSD ...
, and
NetBSD
NetBSD is a free and open-source Unix-like operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was fork (software development), forked. It continues to ...
, 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
Copyleft is the legal technique of granting certain freedoms over copies of copyrighted works with the requirement that the same rights be preserved in derivative works. In this sense, ''freedoms'' refers to the use of the work for any purpose, ...
as restrictive. They generally advocate
permissive free software licenses, which allow others to use the software as they wish, without being legally ''forced'' to provide the source code. Their view is that this permissive approach is more free. The
Kerberos,
X11, and
Apache software licenses are substantially similar in intent and implementation.
Examples
There are thousands of free applications and many operating systems available on the Internet. Users can easily download and install those applications via a
package manager
A package manager or package management system is a collection of software tools that automates the process of installing, upgrading, configuring, and removing computer programs for a computer in a consistent manner.
A package manager deals wi ...
that comes included with most
Linux distributions.
The
Free Software Directory maintains a large database of free-software packages. Some of the best-known examples include
Linux-libre
According to the Free_Software_Foundation_Latin_America , Free Software Foundation Latin America, Linux-libre is a modified version of the Linux kernel that contains no binary blobs, Obfuscation (software), obfuscated code, or code released u ...
, Linux-based operating systems, the
GNU Compiler Collection
The GNU Compiler Collection (GCC) is a collection of compilers from the GNU Project that support various programming languages, Computer architecture, hardware architectures, and operating systems. The Free Software Foundation (FSF) distributes ...
and
C library; the
MySQL
MySQL () is an Open-source software, open-source relational database management system (RDBMS). Its name is a combination of "My", the name of co-founder Michael Widenius's daughter My, and "SQL", the acronym for Structured Query Language. A rel ...
relational database; the
Apache web server; and the
Sendmail mail transport agent. Other influential examples include the
Emacs
Emacs (), originally named EMACS (an acronym for "Editor Macros"), is a family of text editors that are characterized by their extensibility. The manual for the most widely used variant, GNU Emacs, describes it as "the extensible, customizable, s ...
text editor; the
GIMP
Gimp or GIMP may refer to:
Clothing
* Bondage suit, also called a gimp suit, a type of suit used in BDSM
* Bondage mask, also called a gimp mask, often worn in conjunction with a gimp suit
Embroidery and crafts
* Gimp (thread), an ornamental tr ...
raster drawing and image editor; the
X Window System
The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems.
X originated as part of Project Athena at Massachusetts Institute of Technology (MIT) in 1984. The X protocol has been at ...
graphical-display system; the
LibreOffice office suite; and the
TeX
Tex, TeX, TEX, may refer to:
People and fictional characters
* Tex (nickname), a list of people and fictional characters with the nickname
* Tex Earnhardt (1930–2020), U.S. businessman
* Joe Tex (1933–1982), stage name of American soul singer ...
and
LaTeX
Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latices are found in nature, but synthetic latices are common as well.
In nature, latex is found as a wikt:milky, milky fluid, which is present in 10% of all floweri ...
typesetting systems.
History
From the 1950s up until the early 1970s, it was normal for computer users to have the ''software freedoms'' associated with free software, which was typically
public-domain software.
Software
Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications.
The history of software is closely tied to the development of digital comput ...
was commonly shared by individuals who used computers and by hardware manufacturers who welcomed the fact that people were making software that made their hardware useful. Organizations of users and suppliers, for example,
SHARE, were formed to facilitate exchange of software. As software was often written in an
interpreted language
In computer science, an interpreter is a computer program that directly executes instructions written in a programming or scripting language, without requiring them previously to have been compiled into a machine language program. An inter ...
such as
BASIC
Basic or BASIC may refer to:
Science and technology
* BASIC, a computer programming language
* Basic (chemistry), having the properties of a base
* Basic access authentication, in HTTP
Entertainment
* Basic (film), ''Basic'' (film), a 2003 film
...
, the
source code
In computing, source code, or simply code or source, is a plain text computer program written in a programming language. A programmer writes the human readable source code to control the behavior of a computer.
Since a computer, at base, only ...
was distributed to use these programs. Software was also shared and distributed as printed source code (
Type-in program) in
computer magazine
Computer magazines are about computers and related subjects, such as networking and the Internet. Most computer magazines offer (or offered) advice, some offer programming tutorials, reviews of the latest technologies, and advertisements.
...
s (like ''
Creative Computing'', ''
SoftSide'', ''
Compute!'', ''
Byte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable un ...
'', etc.) and books, like the bestseller ''
BASIC Computer Games''. By the early 1970s, the picture changed: 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
International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...
'', filed January 17, 1969, the government charged that bundled software was
anti-competitive.
While some software might always be free, there would henceforth be a growing amount of software produced primarily for sale. In the 1970s and early 1980s, the
software industry
The software industry includes businesses for development, maintenance and publication of software that are using different business models, mainly either "license/maintenance based" (on-premises) or " Cloud based" (such as SaaS, PaaS, IaaS, ...
began using technical measures (such as only distributing
binary copies of
computer program
A computer program is a sequence or set of instructions in a programming language for a computer to Execution (computing), execute. It is one component of software, which also includes software documentation, documentation and other intangibl ...
s) to prevent
computer users from being able to study or adapt the software applications as they saw fit. In 1980,
copyright
A copyright is a type of intellectual property that gives its owner the exclusive legal right to copy, distribute, adapt, display, and perform a creative work, usually for a limited time. The creative work may be in a literary, artistic, ...
law was extended to computer programs.
In 1983,
Richard Stallman
Richard Matthew Stallman ( ; born March 16, 1953), also known by his initials, rms, is an American free software movement activist and programmer. He campaigns for software to be distributed in such a manner that its users have the freedom to ...
, one of the original authors of the popular
Emacs
Emacs (), originally named EMACS (an acronym for "Editor Macros"), is a family of text editors that are characterized by their extensibility. The manual for the most widely used variant, GNU Emacs, describes it as "the extensible, customizable, s ...
program and a longtime member of the
hacker
A hacker is a person skilled in information technology who achieves goals and solves problems by non-standard means. The term has become associated in popular culture with a security hackersomeone with knowledge of bug (computing), bugs or exp ...
community at the
MIT Artificial Intelligence Laboratory, announced the
GNU Project
The GNU Project ( ) is a free software, mass collaboration project announced by Richard Stallman on September 27, 1983. Its goal is to give computer users freedom and control in their use of their computers and Computer hardware, computing dev ...
, the purpose of which was to produce a completely non-proprietary
Unix-compatible operating system, saying that he had become frustrated with the shift in climate surrounding the computer world and its users. In his initial declaration of the project and its purpose, he specifically cited as a motivation his opposition to being asked to agree to
non-disclosure agreement
A non-disclosure agreement (NDA), also known as a confidentiality agreement (CA), confidential disclosure agreement (CDA), proprietary information agreement (PIA), or secrecy agreement (SA), is a legal contract or part of a contract between at le ...
s and restrictive licenses which prohibited the free sharing of potentially profitable in-development software, a prohibition directly contrary to the traditional
hacker ethic. Software development for the
GNU operating system began in January 1984, and the
Free Software Foundation
The Free Software Foundation (FSF) is a 501(c)(3) non-profit organization founded by Richard Stallman on October 4, 1985. The organisation supports the free software movement, with the organization's preference for software being distributed ...
(FSF) was founded in October 1985. He developed a free software definition and the concept of "
copyleft
Copyleft is the legal technique of granting certain freedoms over copies of copyrighted works with the requirement that the same rights be preserved in derivative works. In this sense, ''freedoms'' refers to the use of the work for any purpose, ...
", designed to ensure ''software freedom'' for all.
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
Copyleft is the legal technique of granting certain freedoms over copies of copyrighted works with the requirement that the same rights be preserved in derivative works. In this sense, ''freedoms'' refers to the use of the work for any purpose, ...
licenses (''see the
OpenCores project, for instance'').
Creative Commons
Creative Commons (CC) is an American non-profit organization and international network devoted to educational access and expanding the range of creative works available for others to build upon legally and to share. The organization has release ...
and the
free-culture movement have also been largely influenced by the free software movement.
1980s: Foundation of the GNU Project
In 1983,
Richard Stallman
Richard Matthew Stallman ( ; born March 16, 1953), also known by his initials, rms, is an American free software movement activist and programmer. He campaigns for software to be distributed in such a manner that its users have the freedom to ...
, longtime member of the
hacker
A hacker is a person skilled in information technology who achieves goals and solves problems by non-standard means. The term has become associated in popular culture with a security hackersomeone with knowledge of bug (computing), bugs or exp ...
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
The Free Software Foundation (FSF) is a 501(c)(3) non-profit organization founded by Richard Stallman on October 4, 1985. The organisation supports the free software movement, with the organization's preference for software being distributed ...
(FSF) was founded in October 1985. An article outlining the project and its goals was published in March 1985 titled the ''
GNU Manifesto
__NOTOC__
The ''GNU Manifesto'' is a direct action, call-to-action by Richard Stallman encouraging participation and support of the GNU Project's goal in developing the GNU free software, free computer operating system. The GNU Manifesto was publ ...
''. The manifesto included significant explanation of the GNU philosophy, ''
Free Software Definition'' and "
copyleft
Copyleft is the legal technique of granting certain freedoms over copies of copyrighted works with the requirement that the same rights be preserved in derivative works. In this sense, ''freedoms'' refers to the use of the work for any purpose, ...
" ideas.
1990s: Release of the Linux kernel
The
Linux kernel
The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the k ...
, started by
Linus Torvalds
Linus Benedict Torvalds ( , ; born 28 December 1969) is a Finnish software engineer who is the creator and lead developer of the Linux kernel. He also created the distributed version control system Git.
He was honored, along with Shinya Yam ...
, was released as freely modifiable source code in 1991. The first licence was a proprietary software licence. However, with version 0.12 in February 1992, he
relicensed the project under the
GNU General Public License
The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first ...
. Much like Unix, Torvalds' kernel attracted the attention of volunteer programmers.
FreeBSD
FreeBSD is a free-software Unix-like operating system descended from the Berkeley Software Distribution (BSD). The first version was released in 1993 developed from 386BSD, one of the first fully functional and free Unix clones on affordable ...
and
NetBSD
NetBSD is a free and open-source Unix-like operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was fork (software development), forked. It continues to ...
(both derived from
386BSD) were released as free software when the ''
USL v. BSDi'' lawsuit was settled out of court in 1993.
OpenBSD
OpenBSD is a security-focused operating system, security-focused, free software, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by fork (software development), forking NetBSD ...
forked from NetBSD in 1995. Also in 1995, The
Apache HTTP Server
The Apache HTTP Server ( ) is a free and open-source software, free and open-source cross-platform web server, released under the terms of Apache License, Apache License 2.0. It is developed and maintained by a community of developers under the ...
, commonly referred to as Apache, was released under the
Apache License 1.0.
Licensing

All free-software licenses must grant users 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 falls under a small set of licenses. The most popular of these licenses are:
* The
MIT License
The MIT License is a permissive software license originating at the Massachusetts Institute of Technology (MIT) in the late 1980s. As a permissive license, it puts very few restrictions on reuse and therefore has high license compatibility.
Unl ...
* The
GNU General Public License v2 (GPLv2)
* The
Apache License
The Apache License is a permissive free software license written by the Apache Software Foundation (ASF). It allows users to use the software for any purpose, to distribute it, to modify it, and to distribute modified versions of the software ...
* The
GNU General Public License v3 (GPLv3)
* The
BSD License
* The
GNU Lesser General Public License (LGPL)
* The
Mozilla Public License
The Mozilla Public License (MPL) is a free and open-source weak copyleft license for most Mozilla Foundation software such as Firefox and Thunderbird. The MPL is developed and maintained by Mozilla, which seeks to balance the concerns of bo ...
(MPL)
* The
Eclipse Public License
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:
*
List of FSF approved software licenses
This comparison only covers software licenses which have a linked Wikipedia article for details and which are approved by at least one of the following expert groups: the Free Software Foundation, the Open Source Initiative, the Debian Project and ...
*
List of OSI approved software licenses
The FSF list is not prescriptive: free-software licenses can exist that the FSF has not heard about, or considered important enough to write about. So it is possible for a license to be free and not in the FSF list. The OSI list only lists licenses that have been submitted, considered and approved. All open-source licenses must meet the
Open Source Definition in order to be officially recognized as open source software. Free software, on the other hand, is a more informal classification that does not rely on official recognition. Nevertheless, software licensed under licenses that do not meet the Free Software Definition cannot rightly be considered free software.
Apart from these two organizations, the
Debian
Debian () is a free and open-source software, free and open source Linux distribution, developed by the Debian Project, which was established by Ian Murdock in August 1993. Debian is one of the oldest operating systems based on the Linux kerne ...
project is seen by some to provide useful advice on whether particular licenses comply with their
Debian Free Software Guidelines. Debian does not publish a list of 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 announced as being in-compliance with the FSF guidelines does not also meet the
Open Source Definition, although the reverse is not necessarily true (for example, the
NASA Open Source Agreement is an OSI-approved license, but non-free according to FSF).
There are different categories of free software.
*
Public-domain software: the copyright has expired, the work was not copyrighted (released without
copyright notice before 1988), or the author has released the software onto the public domain with a
waiver
A waiver is the voluntary relinquishment or surrender of some known right or privilege.
A waiver is often written, such as a disclaimer that has been accepted, but it may also be spoken between two or more parties. When the right to hold a ...
statement (in countries where this is possible). Since public-domain software lacks copyright protection, it may be freely incorporated into any work, whether proprietary or free. The FSF recommends the
CC0 public domain dedication for this purpose.
*
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 modification, even closed-source ones.
*
Copyleft
Copyleft is the legal technique of granting certain freedoms over copies of copyrighted works with the requirement that the same rights be preserved in derivative works. In this sense, ''freedoms'' refers to the use of the work for any purpose, ...
licenses, with the
GNU General Public License
The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first ...
being the most prominent: the author retains copyright and permits redistribution under the restriction that 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. This is also known as a
''viral'', ''
protective'', or ''reciprocal'' license.
Proponents of permissive and copyleft licenses disagree on whether software freedom should be viewed as a
negative or
positive liberty
Positive liberty, or positive freedom, is the possession of the power and resources to act in the context of the structural limitations of the broader society which impacts a person's ability to act, as opposed to negative liberty, which is freed ...
. Due to their restrictions on distribution, not everyone considers copyleft licenses to be free. Conversely, a permissive license may provide an incentive to create non-free software by reducing the cost of developing restricted software. Since this is incompatible with the spirit of software freedom, many people consider permissive licenses to be less free than copyleft licenses.
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 that lack fixes for known security flaws, at least until a fix is available.
Free software advocates strongly believe that this methodology is biased by counting more vulnerabilities for the free software systems, since their source code is accessible and their community is more forthcoming about what problems exist as a part of
full disclosure,
and proprietary software systems can have undisclosed societal drawbacks, such as disenfranchising less fortunate would-be users of free programs. 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. According to Richard Stallman, user access to the source code makes deploying free software with undesirable hidden
spyware
Spyware (a portmanteau for spying software) is any malware that aims to gather information about a person or organization and send it to another entity in a way that harms the user by violating their privacy, endangering their device's securit ...
functionality far more difficult than for proprietary software.
Some quantitative studies have been done on the subject.
Binary blobs and other proprietary software
In 2006,
OpenBSD
OpenBSD is a security-focused operating system, security-focused, free software, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by fork (software development), forking NetBSD ...
started the first campaign against the use of
binary blobs in
kernels. Blobs are usually freely distributable
device driver
In the context of an operating system, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer or automaton. A driver provides a software interface to hardware devices, enabli ...
s for hardware from vendors that do not reveal driver source code to users or developers. This restricts the users' freedom effectively to 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
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ...
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
The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the k ...
and other device drivers motivated some developers in Ireland to launch
gNewSense, a Linux-based distribution with all the binary blobs removed. The project received support from the
Free Software Foundation
The Free Software Foundation (FSF) is a 501(c)(3) non-profit organization founded by Richard Stallman on October 4, 1985. The organisation supports the free software movement, with the organization's preference for software being distributed ...
and stimulated the creation, headed by the
Free Software Foundation Latin America, of the
Linux-libre
According to the Free_Software_Foundation_Latin_America , Free Software Foundation Latin America, Linux-libre is a modified version of the Linux kernel that contains no binary blobs, Obfuscation (software), obfuscated code, or code released u ...
kernel.
,
Trisquel is the most popular FSF endorsed Linux distribution ranked by Distrowatch (over 12 months).
While
Debian
Debian () is a free and open-source software, free and open source Linux distribution, developed by the Debian Project, which was established by Ian Murdock in August 1993. Debian is one of the oldest operating systems based on the Linux kerne ...
is not endorsed by the FSF and does not use Linux-libre, it is also a popular distribution available without kernel blobs by default since 2011.
The Linux community uses the term "blob" to refer to all nonfree firmware in a kernel whereas OpenBSD uses the term to refer to device drivers. The FSF does not consider OpenBSD to be blob free under the Linux community's definition of blob.
Business model
Selling software under any free-software licence is permissible, as is commercial use. This is true for licenses with or without
copyleft
Copyleft is the legal technique of granting certain freedoms over copies of copyrighted works with the requirement that the same rights be preserved in derivative works. In this sense, ''freedoms'' refers to the use of the work for any purpose, ...
.
Since free software may be freely redistributed, it is generally available at little or no fee. Free software business models are usually based on adding value such as customization, accompanying hardware, support, training, integration, or certification.
Exceptions exist however, where the user is charged to obtain a copy of the free application itself.
Fees are usually charged for distribution on compact discs and bootable USB drives, or for services of installing or maintaining the operation of free software. Development of large, commercially used free software is often funded by a combination of user donations,
crowdfunding
Crowdfunding is the practice of funding a project or venture by raising money from a large number of people, typically via the internet. Crowdfunding is a form of crowdsourcing and Alternative Finance, alternative finance, to fund projects "withou ...
, corporate contributions, and tax money. The
SELinux project at the United States
National Security Agency
The National Security Agency (NSA) is an intelligence agency of the United States Department of Defense, under the authority of the director of national intelligence (DNI). The NSA is responsible for global monitoring, collection, and proces ...
is an example of a federally funded free-software project.
Proprietary software, on the other hand, tends to use a different business model, where a customer of the proprietary application pays a fee for a license to legally access and use it. 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.
The Free Software Foundation encourages selling free software. As the Foundation has written, "distributing free software is an opportunity to raise funds for development. Don't waste it!".
For example, the FSF's own recommended license (the
GNU GPL) states that "
oumay charge any price or no price for each copy that you convey, and you may offer support or warranty protection for a fee."
Microsoft CEO
Steve Ballmer
Steven Anthony Ballmer (; March 24, 1956) is an American businessman and investor who served as chief executive officer of Microsoft from 2000 to 2014. He is the owner of the Los Angeles Clippers of the National Basketball Association (NBA). He i ...
stated in 2001 that "open source is not available to commercial companies. The way the license is written, if you use any open-source software, you have to make the rest of your software open source."
This misunderstanding is based on a requirement of
copyleft
Copyleft is the legal technique of granting certain freedoms over copies of copyrighted works with the requirement that the same rights be preserved in derivative works. In this sense, ''freedoms'' refers to the use of the work for any purpose, ...
licenses (like the GPL) that if one distributes modified versions of software, they must release the source and use the same license. This requirement does not extend to other software from the same developer. The claim of incompatibility between commercial companies and free software is also a misunderstanding. There are several large companies, e.g.
Red Hat
Red Hat, Inc. (formerly Red Hat Software, Inc.) is an American software company that provides open source software products to enterprises and is a subsidiary of IBM. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North ...
and
IBM
International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...
(IBM acquired RedHat in 2019), which do substantial commercial business in the development of free software.
Economic aspects and adoption
Free software played a significant 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
Private or privates may refer to:
Music
* "In Private", by Dusty Springfield from the 1990 album ''Reputation''
* Private (band), a Denmark-based band
* "Private" (Ryōko Hirosue song), from the 1999 album ''Private'', written and also recorded ...
. Companies that contribute to free software increase commercial
innovation
Innovation is the practical implementation of ideas that result in the introduction of new goods or service (economics), services or improvement in offering goods or services. ISO TC 279 in the standard ISO 56000:2020 defines innovation as "a n ...
.
The economic viability of free software has been recognized by large corporations such as
IBM
International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...
,
Red Hat
Red Hat, Inc. (formerly Red Hat Software, Inc.) is an American software company that provides open source software products to enterprises and is a subsidiary of IBM. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North ...
, and
Sun Microsystems
Sun Microsystems, Inc., often known as Sun for short, was an American technology company that existed from 1982 to 2010 which developed and sold computers, computer components, software, and information technology services. Sun contributed sig ...
.
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. Most companies in the software business include free software in their commercial products if the licenses allow that.
Free software is generally available at no cost and can result in permanently lower TCO (
total cost of ownership
Total cost of ownership (TCO) is a financial estimate intended to help buyers and owners determine the direct and indirect costs of a product or service. It is a management accounting concept that can be used in full cost accounting or even eco ...
) compared to
proprietary software
Proprietary software is computer software, software that grants its creator, publisher, or other rightsholder or rightsholder partner a legal monopoly by modern copyright and intellectual property law to exclude the recipient from freely sharing t ...
.
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 estimates that adoption of free software has caused a drop in revenue to the proprietary software industry by about $60 billion per year.
Eric S. Raymond argued that the term ''free software'' is too ambiguous and intimidating for the business community. Raymond promoted the term ''
open-source software
Open-source software (OSS) is Software, computer software that is released under a Open-source license, license in which the copyright holder grants users the rights to use, study, change, and Software distribution, distribute the software an ...
'' as a friendlier alternative for the business and corporate world.
See also
*
Definition of Free Cultural Works
*
Digital rights
Digital rights are those human rights and Natural and legal rights, legal rights that allow individuals to access, use, create, and publish digital media or to access and use computers, other Consumer electronics, electronic devices, and teleco ...
*
Free content
*
List of formerly proprietary software
*
List of free software project directories
*
List of free software for Web 2.0 Services
*
Open format
*
Open standard
An open standard is a standard that is openly accessible and usable by anyone. It is also a common prerequisite that open standards use an open license that provides for extensibility. Typically, anybody can participate in their development due to ...
*
Open-source hardware
Open-source hardware (OSH, OSHW) consists of physical artifact (software development), artifacts of technology designed and offered by the open-design movement. Both free and open-source software (FOSS) and open-source hardware are created by th ...
*
Outline of free software
*
:Free software lists and comparisons
*
Appropriate Technology
Appropriate technology is a movement (and its manifestations) encompassing technology, technological choice and application that is small-scale, affordable by its users, labor-intensive, efficient energy use, energy-efficient, environmentally sust ...
*
Sustainable Development
Sustainable development is an approach to growth and Human development (economics), human development that aims to meet the needs of the present without compromising the ability of future generations to meet their own needs.United Nations General ...
*
Gratis versus libre
The adjective ''free'' in English is commonly used in one of two meanings: "at no monetary cost" (''gratis'') or "with little or no restriction" (''libre''). This ambiguity can cause issues where the distinction is important, as it often is in ...
Notes
References
Further reading
Puckette, Miller. "Who Owns our Software?: A first-person case study." eContact (September 2009). Montréal: CECHancock, Terry. "The Jargon of Freedom: 60 Words and Phrases with Context". Free Software Magazine. 2010-20-24
*
External links
{{Authority control
Software licensing
Applied ethics