Free software

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For other uses, see Free software (disambiguation). Free software_sentence_0

Not to be confused with Freeware. Free software_sentence_1

For broader coverage of this topic, see Free software movement. Free software_sentence_2

Free software (or libre software) is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software_sentence_3

Free software is a matter of liberty, 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. Free software_sentence_4

Computer programs are deemed "free" if they give end-users (not just the developer) ultimate control over the software and, subsequently, over their devices. Free software_sentence_5

The right to study and modify a computer program entails that source code—the preferred format for making changes—be made available to users of that program. Free software_sentence_6

While this is often called "access to source code" or "public availability", the Free Software Foundation 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. Free software_sentence_7

Although the term "free software" had already been used loosely in the past, Richard Stallman is credited with tying it to the sense under discussion and starting the free-software movement in 1983, when he launched the GNU Project: a collaborative effort to create a freedom-respecting operating system, and to revive the spirit of cooperation once prevalent among hackers during the early days of computing. Free software_sentence_8

Context Free software_section_0

Free software thus differs from: Free software_sentence_9

Free software_unordered_list_0

For software under the purview of copyright to be free, it must carry a software license whereby the author grants users the aforementioned rights. Free software_sentence_10

Software that is not covered by copyright law, such as software in the public domain, is free as long as the source code is in the public domain too, or otherwise available without restrictions. Free software_sentence_11

Proprietary software uses restrictive software licences or EULAs and usually does not provide users with the source code. Free software_sentence_12

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. Free software_sentence_13

(See also vendor lock-in and abandonware). Free software_sentence_14

Users often may not reverse engineer, modify, or redistribute proprietary software. Free software_sentence_15

Beyond copyright law, contracts and lack of source code, there can exist additional obstacles keeping users from exercising freedom over a piece of software, such as software patents and digital rights management (more specifically, tivoization). Free software_sentence_16

Free software can be a for-profit, commercial activity or not. Free software_sentence_17

Some free software is developed by volunteer computer programmers while other is developed by corporations; or even by both. Free software_sentence_18

Naming and differences with Open Source Free software_section_1

Main article: Alternative terms for free software Free software_sentence_19

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" (a younger vision coined in 1998), because the goals and messaging are quite dissimilar. Free software_sentence_20

"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. Free software_sentence_21

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. Free software_sentence_22

The FSF also notes that "Open Source" has exactly one specific meaning in common English, namely that "you can look at the source code." Free software_sentence_23

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". Free software_sentence_24

The loan adjective "" is often used to avoid the ambiguity of the word "free" in English language, and the ambiguity with the older usage of "free software" as public-domain software. Free software_sentence_25

See Gratis versus libre. Free software_sentence_26

Definition and the Four Essential Freedoms of Free Software Free software_section_2

Main article: The Free Software Definition Free software_sentence_27

See also: Debian Free Software Guidelines and Open Source Definition Free software_sentence_28

The first formal definition of free software was published by Free Software Foundation (FSF) in February 1986. Free software_sentence_29

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. Free software_sentence_30

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. Free software_sentence_31

Free software_unordered_list_1

  • Freedom 0: The freedom to run the program for any purpose.Free software_item_1_2
  • Freedom 1: The freedom to study how the program works, and change it to make it do what you wish.Free software_item_1_3
  • Freedom 2: The freedom to redistribute and make copies so you can help your neighbour.Free software_item_1_4
  • 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.Free software_item_1_5

Freedoms 1 and 3 require source code to be available because studying and modifying software without its source code can range from highly impractical to nearly impossible. Free software_sentence_32

Thus, free software means that computer users have the freedom to cooperate with whom they choose, and to control the software they use. Free software_sentence_33

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. Free software_sentence_34

To understand the concept, you should think of 'free' as in 'free speech', not as in 'free beer'". Free software_sentence_35

See Gratis versus libre. Free software_sentence_36

In the late 1990s, other groups published their own definitions that describe an almost identical set of software. Free software_sentence_37

The most notable are Debian Free Software Guidelines published in 1997, and the Open Source Definition, published in 1998. Free software_sentence_38

The BSD-based operating systems, such as FreeBSD, OpenBSD, and NetBSD, do not have their own formal definitions of free software. Free software_sentence_39

Users of these systems generally find the same set of software to be acceptable, but sometimes see copyleft as restrictive. Free software_sentence_40

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. Free software_sentence_41

Their view is that this permissive approach is more free. Free software_sentence_42

The Kerberos, X11, and Apache software licenses are substantially similar in intent and implementation. Free software_sentence_43

Examples Free software_section_3

Main article: List of free and open-source software packages Free software_sentence_44

There are thousands of free applications and many operating systems available on the Internet. Free software_sentence_45

Users can easily download and install those applications via a package manager that comes included with most Linux distributions. Free software_sentence_46

The Free Software Directory maintains a large database of free-software packages. Free software_sentence_47

Some of the best-known examples include the Linux kernel, the BSD and Linux operating systems, the GNU Compiler Collection and C library; the MySQL relational database; the Apache web server; and the Sendmail mail transport agent. Free software_sentence_48

Other influential examples include the Emacs text editor; the GIMP raster drawing and image editor; the X Window System graphical-display system; the LibreOffice office suite; and the TeX and LaTeX typesetting systems. Free software_sentence_49

History Free software_section_4

Further information: History of free and open-source software Free software_sentence_50

See also: Open-source software § History Free software_sentence_51

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. Free software_sentence_52

Software 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. Free software_sentence_53

Organizations of users and suppliers, for example, SHARE, were formed to facilitate exchange of software. Free software_sentence_54

As software was often written in an interpreted language such as BASIC, the source code was distributed to use these programs. Free software_sentence_55

Software was also shared and distributed as printed source code (Type-in program) in computer magazines (like Creative Computing, SoftSide, Compute! Free software_sentence_56 , Byte etc) and books, like the bestseller BASIC Computer Games. Free software_sentence_57

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. Free software_sentence_58

In United States vs. IBM, filed January 17, 1969, the government charged that bundled software was anti-competitive. Free software_sentence_59

While some software might always be free, there would henceforth be a growing amount of software produced primarily for sale. Free software_sentence_60

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 or adapt the software applications as they saw fit. Free software_sentence_61

In 1980, copyright law was extended to computer programs. Free software_sentence_62

In 1983, Richard Stallman, one of the original authors of the popular Emacs program and a longtime member of the hacker community at the MIT Artificial Intelligence Laboratory, announced the GNU project, 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. Free software_sentence_63

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 agreements and restrictive licenses which prohibited the free sharing of potentially profitable in-development software, a prohibition directly contrary to the traditional hacker ethic. Free software_sentence_64

Software development for the GNU operating system began in January 1984, and the Free Software Foundation (FSF) was founded in October 1985. Free software_sentence_65

He developed a free software definition and the concept of "copyleft", designed to ensure software freedom for all. Free software_sentence_66

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). Free software_sentence_67

Creative Commons and the free-culture movement have also been largely influenced by the free software movement. Free software_sentence_68

1980s: Foundation of the GNU project Free software_section_5

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. Free software_sentence_69

Software development for the GNU operating system began in January 1984, and the Free Software Foundation (FSF) was founded in October 1985. Free software_sentence_70

An article outlining the project and its goals was published in March 1985 titled the GNU Manifesto. Free software_sentence_71

The manifesto included significant explanation of the GNU philosophy, Free Software Definition and "copyleft" ideas. Free software_sentence_72

1990s: Release of the Linux kernel Free software_section_6

The Linux kernel, started by Linus Torvalds, was released as freely modifiable source code in 1991. Free software_sentence_73

The first licence was a proprietary software licence. Free software_sentence_74

However, with version 0.12 in February 1992, he relicensed the project under the GNU General Public License. Free software_sentence_75

Much like Unix, Torvalds' kernel attracted the attention of volunteer programmers. Free software_sentence_76

FreeBSD and NetBSD (both derived from 386BSD) were released as free software when the USL v. BSDi lawsuit was settled out of court in 1993. Free software_sentence_77

OpenBSD forked from NetBSD in 1995. Free software_sentence_78

Also in 1995, The Apache HTTP Server, commonly referred to as Apache, was released under the Apache License 1.0. Free software_sentence_79

Licensing Free software_section_7

Main article: Free-software license Free software_sentence_80

Further information: Open-source license Free software_sentence_81

See also: Free and open-source software § Licensing Free software_sentence_82

All free-software licenses must grant users all the freedoms discussed above. Free software_sentence_83

However, unless the applications' licenses are compatible, combining programs by mixing source code or directly linking binaries is problematic, because of license technicalities. Free software_sentence_84

Programs indirectly connected together may avoid this problem. Free software_sentence_85

The majority of free software falls under a small set of licenses. Free software_sentence_86

The most popular of these licenses are: Free software_sentence_87

Free software_unordered_list_2

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: Free software_sentence_88

Free software_unordered_list_3

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. Free software_sentence_89

So it's possible for a license to be free and not in the FSF list. Free software_sentence_90

The OSI list only lists licenses that have been submitted, considered and approved. Free software_sentence_91

All open-source licenses must meet the Open Source Definition in order to be officially recognized as open source software. Free software_sentence_92

Free software, on the other hand, is a more informal classification that does not rely on official recognition. Free software_sentence_93

Nevertheless, software licensed under licenses that do not meet the Free Software Definition cannot rightly be considered free software. Free software_sentence_94

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. Free software_sentence_95

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. Free software_sentence_96

That is summarized at the Debian web site. Free software_sentence_97

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). Free software_sentence_98

There are different categories of free software. Free software_sentence_99

Free software_unordered_list_4

  • 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 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.Free software_item_4_16
  • Permissive licenses, also called BSD-style because they are applied to much of the software distributed with the BSD operating systems: many of these licenses are also known as copyfree as they have no restrictions on distribution. The author retains copyright solely to disclaim warranty and require proper attribution of modified works, and permits redistribution and any modification, even closed-source ones. In this sense, a permissive license provides 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.Free software_item_4_17
  • Copyleft licenses, with the GNU General Public License 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. Due to the restriction on distribution not everyone considers this type of license to be free.Free software_item_4_18

Security and reliability Free software_section_8

There is debate over the security of free software in comparison to proprietary software, with a major issue being security through obscurity. Free software_sentence_100

A popular quantitative test in computer security is to use relative counting of known unpatched security flaws. Free software_sentence_101

Generally, users of this method advise avoiding products that lack fixes for known security flaws, at least until a fix is available. Free software_sentence_102

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, (This is called "Security Through Disclosure") and proprietary software systems can have undisclosed societal drawbacks, such as disenfranchising less fortunate would-be users of free programs. Free software_sentence_103

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. Free software_sentence_104

According to Richard Stallman, user access to the source code makes deploying free software with undesirable hidden spyware functionality far more difficult than for proprietary software. Free software_sentence_105

Some quantitative studies have been done on the subject. Free software_sentence_106

Binary blobs and other proprietary software Free software_section_9

In 2006, OpenBSD started the first campaign against the use of binary blobs in kernels. Free software_sentence_107

Blobs are usually freely distributable device drivers for hardware from vendors that do not reveal driver source code to users or developers. Free software_sentence_108

This restricts the users' freedom effectively to modify the software and distribute modified versions. Free software_sentence_109

Also, since the blobs are undocumented and may have bugs, they pose a security risk to any operating system whose kernel includes them. Free software_sentence_110

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. Free software_sentence_111

The issue of binary blobs in the Linux kernel and other device drivers motivated some developers in Ireland to launch gNewSense, a Linux based distribution with all the binary blobs removed. Free software_sentence_112

The project received support from the Free Software Foundation and stimulated the creation, headed by the Free Software Foundation Latin America, of the Linux-libre kernel. Free software_sentence_113

As of October 2012, Trisquel is the most popular FSF endorsed Linux distribution ranked by Distrowatch (over 12 months). Free software_sentence_114

While Debian 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. Free software_sentence_115

Business model Free software_section_10

See also: Business models for open-source software Free software_sentence_116

Selling software under any free-software licence is permissible, as is commercial use. Free software_sentence_117

This is true for licenses with or without copyleft. Free software_sentence_118

Since free software may be freely redistributed, it is generally available at little or no fee. Free software_sentence_119

Free software business models are usually based on adding value such as customization, accompanying hardware, support, training, integration, or certification. Free software_sentence_120

Exceptions exist however, where the user is charged to obtain a copy of the free application itself. Free software_sentence_121

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. Free software_sentence_122

Development of large, commercially used free software is often funded by a combination of user donations, crowdfunding, corporate contributions, and tax money. Free software_sentence_123

The SELinux project at the United States National Security Agency is an example of a federally funded free-software project. Free software_sentence_124

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. Free software_sentence_125

This license may grant the customer the ability to configure some or no parts of the software themselves. Free software_sentence_126

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. Free software_sentence_127

Some proprietary software vendors will also customize software for a fee. Free software_sentence_128

The Free Software Foundation encourages selling free software. Free software_sentence_129

As the Foundation has written, "distributing free software is an opportunity to raise funds for development. Free software_sentence_130

Don't waste it!". Free software_sentence_131

For example, the FSF's own recommended license (the GNU GPL) states that "[you] may charge any price or no price for each copy that you convey, and you may offer support or warranty protection for a fee." Free software_sentence_132

Microsoft CEO Steve Ballmer stated in 2001 that "open source is not available to commercial companies. Free software_sentence_133

The way the license is written, if you use any open-source software, you have to make the rest of your software open source." Free software_sentence_134

This misunderstanding is based on a requirement of copyleft licenses (like the GPL) that if one distributes modified versions of software, they must release the source and use the same license. Free software_sentence_135

This requirement does not extend to other software from the same developer. Free software_sentence_136

The claim of incompatibility between commercial companies and free software is also a misunderstanding. Free software_sentence_137

There are several large companies, e.g. Red Hat and IBM, which do substantial commercial business in the development of free software. Free software_sentence_138

Economic aspects and adoption Free software_section_11

Main article: Free and open-source software § Adoption Free software_sentence_139

See also: Linux adoption and Open-source software § Adoption Free software_sentence_140

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_sentence_141

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. Free software_sentence_142

Companies that contribute to free software increase commercial innovation. Free software_sentence_143

The economic viability of free software has been recognized by large corporations such as IBM, Red Hat, and Sun Microsystems. Free software_sentence_144

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. Free software_sentence_145

Most companies in the software business include free software in their commercial products if the licenses allow that. Free software_sentence_146

Free software is generally available at no cost and can result in permanently lower TCO costs compared to proprietary software. Free software_sentence_147

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_sentence_148

Free software often has no warranty, and more importantly, generally does not assign legal liability to anyone. Free software_sentence_149

However, warranties are permitted between any two parties upon the condition of the software and its usage. Free software_sentence_150

Such an agreement is made separately from the free software license. Free software_sentence_151

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. Free software_sentence_152

Eric S. Raymond argued that the term free software is too ambiguous and intimidating for the business community. Free software_sentence_153

Raymond promoted the term open-source software as a friendlier alternative for the business and corporate world. Free software_sentence_154

See also Free software_section_12

Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Free software.