Open-source license

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BSD Licenses, the GNU Lesser General Public License (LGPL) and the Mozilla Public License
(MPL).

Open-source licenses are

Open Source Definition
.

After 1980, the United States began to treat software as a literary work covered by copyright law.

free software licenses describe the same type of licenses.[1]

The two main categories of open-source licenses are

derivative works
to be distributed with the source code and under a similar license. Since the mid-2000s, courts in multiple countries have upheld the terms of both types of license. Software developers have filed cases as copyright infringement and as breaches of contract.

Background

Main article: History of free and open-source software
Legal scholar Eben Moglen on the history of copyright

copyrights.[4]

Most countries, including the United States (US), have

derivative works.[8] When a creator modifies an existing work, they hold the copyright to their modifications.[9] Unless the original work was in the public domain, a derivative work can only be distributed with the permission of every copyright holder.[10]

In 1980, the US government amended the law to treat software as a literary work. Software released after this point was restricted by IP laws.

activist and programmer Richard Stallman was working as a graduate student at the MIT Computer Science and Artificial Intelligence Laboratory. Stallman witnessed fragmentation among software developers. He blamed the spread of proprietary software and closed models of development. To push back against these trends, Stallman founded the free software movement.[12] Throughout the 1980s, he started the GNU Project to create a free operating system, wrote essays on freedom, founded the Free Software Foundation (FSF), and wrote several free software licenses.[13] The FSF used existing intellectual property laws for the opposite of their intended goal of restriction. Instead of imposing restrictions, free software explicitly provided freedoms to the recipient.[14]

Open Source Definition

In the 90s, the term "open source" was coined as an alternative label for free software, and specific criteria were laid out to determine which licenses covered free and open-source software.[15][16] Two active members of the free software community, Bruce Perens and Eric S. Raymond, founded the Open Source Initiative (OSI).[17] At Debian, Perens had proposed the Debian Free Software Guidelines (DFSG).[18] The DFSG were drafted to provide a more specific and objective standard for the FOSS that Debian would host in their repositories.[19] The OSI adopted the DSFG and used them as the basis for their Open Source Definition.[20] The Free Software Foundation maintains a rival set of criteria, the Free Software Definition.[21] Historically, these three organizations and their sets of criteria have been the notable authorities in determining whether a license covers free and open-source software.[22] There is significant diversity among individual licenses but little difference between the rival definitions.[16] The three definitions each require that people receiving covered software must be able to use, modify, and redistribute the covered work.[23]

Eric S. Raymond was a proponent of the term "open source" over "free software". He viewed open source as more appealing to businesses and more reflective of the tangible advantages of FOSS development. One of Raymond's goals was to expand the existing hacker community to include large commercial developers.[24] In The Cathedral and the Bazaar, Raymond compared open-source development to the bazaar, an open-air public market.[25] He argued that aside from ethics, the open model provided advantages that proprietary software could not replicate.[26][27] Raymond focused heavily on feedback, testing, and bug reports.[28] He contrasted the proprietary model where small pools of secretive workers carried out this work with the development of Linux where the pool of testers included potentially the entire world.[29] He summarized this strength as "Given enough eyeballs, all bugs are shallow."[30] The OSI succeeded in bringing open-source development to corporate developers including Sun Microsystems, IBM, Netscape, Mozilla, Apache, Apple Inc., Microsoft, and Nokia. These companies released code under existing licenses and drafted their own to be approved by the OSI.[31][32]

Types

See also: Comparison of free and open-source software licenses

Open-source licenses are categorized as copyleft or permissive.[33] Copyleft licenses require derivative works to include source code under a similar license. Permissive licenses do not, and therefore the code can be used within proprietary software. Copyleft can be further divided into strong and weak depending on whether they define derivative works broadly or narrowly.[34][35]

Licenses focus on copyright law, but code is also covered by other forms of IP.

Software patents cover ideas and, rather than a specific implementation, cover any implementation of a claim. Patent claims give the holder the right to exclude others from making, using, selling, or importing products based on the idea. Because patents grant the right to exclude rather than the right to create, it is possible to have a patent on an idea but still be unable to legally implement it if the invention relies on another patented idea. Thus, open-source patent grants can offer permission only from covered patents. They cannot guarantee that a third party has not patented any concepts embodied in the code.[36] The older permissive licenses do not discuss patents directly and offer only implicit patent grants in their offers to use or sell covered material.[38] Newer copyleft licenses and the 2004 Apache License offer explicit patent grants and limited protection from patent litigation.[39] These patent retaliation clauses protect developers by terminating grants for any party who initiates a patent lawsuit regarding covered software.[39]

Trademarks are the only form of IP not shared by free and open-source software. Trademarks on FOSS function the same as any other trademark.[40] A trademark is a design that identifies the distinct source of a product. Because they distinguish products, the same designs can be used in different fields where there is no risk of confusing similar sources.[41] To give up control of a trademark would result in the loss of that trademark. Therefore, no open-source license freely offers the use of a trademark.[42]

Trademark restrictions can overlap copyrights and affect material otherwise freely available.[43] The US Supreme Court described using trademark law to restrict public domain content as "mutant copyright".[44] In Dastar Corp. v. Twentieth Century Fox Film Corp., the court "caution[ed] against misuse or over-extension of trademark" law without providing a firm decision on those mutant copyrights.[45][46] Trademark overlap can leave open-source and free content projects vulnerable to a "hostile takeover" if outside parties file for trademarks on derivative works.[47] Notably, Andrey Duskin applied for trademarks on the SCP Foundation, a collaborative writing project, when creating derivative works based on SCP stories.[48]

Permissive

Main article: Permissive software license
M I T campus at night
Permissive licenses generally originate in academic institutions like the Massachusetts Institute of Technology.

Permissive licenses, also known as academic licenses,[49] allow recipients to use, modify, and distribute software with no obligation to provide source code. Institutions created these licenses to distribute their creations to the public.[49] Permissive licenses are usually short, often less than a page of text. They impose few conditions. Most include disclaimers of warranty and obligations to credit authors. A few include explicit provisions for patents, trademarks, and other forms of intellectual property.[50]

The

BSD licenses brought the concept of academic freedom of ideas to computing. Early academic software authors had shared code based on implied promises. Berkeley made these concepts explicit with clear disclaimers for liability and warranty along with conditions, or clauses, for redistribution. The original had four clauses, but subsequent versions have further reduced the restrictions. As a result, it's common to specify if the covered software uses a 2-clause or 3-clause version.[51][52]

The

MIT license clarified the conditions by making them more explicit.[53] For example, the MIT license describes the right to sublicense.[54] One of the strengths of open-source development is the continual process where developers can build on the derivative works of each other and combine their projects into collective works. Explicitly making covered code sublicensable provides a legal advantage when tracking the chain of authorship.[53] The BSD and MIT are template licenses that can be adapted to any project. They are widely adapted and used by many FOSS projects.[51]

The

patent trolling.[59]

Copyleft

Main article: Copyleft
A sticker reads, "Copyleft circled letter L".
The Copyleft sticker from an envelope Don Hopkins mailed to Richard Stallman in 1984

Copyleft licenses require source code to be distributed with software and require the source code to be made available under a similar license.[34][60] Like the permissive licenses, most copyleft licenses require attribution.[61] Most, including the GPL, disclaim implied warranties.[62]

Copyleft uses the restrictions of IP law—contrary to their usual purpose—to mandate that the code remain open.[63] The term and it's related slogan, "All rights reversed", had been previously used in a playful manner by the Principia Discordia and Tiny BASIC; the modern usage begins with Richard Stallman's efforts to create a free operating system. In 1984, programmer Don Hopkins mailed a manual to Stallman with a "Copyleft Ⓛ" sticker. Stallman, who was working on the GNU operating system, adopted the term.[64] An early version of copyleft licensing was used for the 1985 release of GNU Emacs.[14][65] The term became associated with the FSF's later reciprocal licenses, notably the GNU General Public License (GPL).[66]

Traditional, proprietary software licenses are written with the goal of increasing

GPL.[72]

Portrait of Mitchell Baker
Mitchell Baker drafted the Mozilla Public License while on Netscape's legal team.[73]

Practical benefits to copyleft licenses have attracted commercial developers. Corporations have used and written reciprocal licenses with a narrower scope than the GPL.

Affero License (AGPL) based on it, use a broad scope to describe affected works. The AGPL extends the reciprocal obligation in the GPL to cover software made available over a network.[74][32] They are called strong copyleft in contrast to the weaker copyleft licenses often used by corporations. Weak copyleft uses narrower, explicit definitions of derivative works.[76][35] The MPL uses a file-based definition, the CPL and EPL use a module-based definition, and the FSF's own LGPL refers to software libraries.[77]

Compatibility

Main article: License compatibility
Chart of license compatibility, full details in section.
Open-source software licenses and how they interact

License compatibility determines how code with different licenses can be distributed together. The goal of open-source licensing is to make the work freely available, but this becomes complicated when working with multiple terminologies imposing different requirements.[78] There are many uncommonly used licenses and some projects write their own bespoke agreements. As a result, this causes more confusion than other legal aspects. When releasing a collection of applications, each license can be considered separately. However, when attempting to combine software, code from another project can only be in-licensed if the project uses compatible terms and conditions.[79]

When combining code bases, the original licenses can be maintained for separate components, and the larger work released under a compatible license.[80] This compatibility is often one-way. Public domain content can be used anywhere as there is no copyright claim, but code acquired under any almost any set of terms cannot be waved to the public domain. Permissive licenses can be used within copyleft works, but copyleft material cannot be released under a permissive license. Some weak copyleft licenses can be used under the GPL and are said to be GPL-compatible. GPL software can only be used under the GPL or AGPL.[78] Permissive licenses are broadly compatible because they can cover separate parts of a project. Multiple licenses including the GPL and Apache License have been revised to enhance compatibility.[81]

Translation issues, ambiguity in licensing terms, and incompatibility of some licenses with the law in certain jurisdictions compound the problem of license compatibility.[82] Downloading an open-source module is straightforward, but complying with the licensing terms can be more difficult.[83] Because of the amount of software dependencies, engineers working on complex projects often rely on license management software to achieve compliance with the licensing terms of open-source components.[84] Many open-source software files do not unambiguously state the license, increasing the difficulties of compliance.[83]

Enforcement

Main article: Open source license litigation
Portrait of Harald Welte
Early legal victories by programmer Harald Welte established a precedent for open-source software litigation in Germany.[85]

Free and open-source software licenses have been successfully enforced in civil court since the mid-2000s.[86] In a pair of early lawsuits—Jacobsen v. Katzer in the United States and Welte v. Sitecom in Germany—defendants argued that open-source licenses were invalid.[87][88] Sitecom and Katzer separately argued that the licenses were unenforceable. Both the US and German courts rejected these claims. They ruled that the defendants could not have legally distributed the software if the licenses were unenforceable.[86][85]

Courts have found that distributing software indicates acceptance of the license's terms.

Online distribution can use clickwrap, a digital equivalent where the user must click to accept.[90] Open-source software has an additional acceptance mechanism. Without permission from the copyright holder, the law prohibits redistribution.[91] Therefore, courts treat redistribution as acceptance of the license terms. These can include attribution provisions or source code provisions for copyleft licenses.[92][93]

Developers typically achieve compliance without lawsuits. Social pressures, like the potential for community backlash, are often sufficient.[94] Cease and desist letters are a common method to bring companies back into compliance, especially in Germany.[95] A standard process has developed in the German legal system. FOSS developers present companies with a cease and desist letter. These letters outline how to come back into compliance from a violation. German judges can issue a court-mandated cease and desist order to unresponsive companies. Civil cases proceed if these first steps fail. The German procedural laws are clear and favorable to claimants.[96]

Uncertainties remain in how different courts will handle certain aspects of licensing.[97] For software in general, there are debates about what can be patented and what can be copyrighted. Regarding an application programming interface (API), the European Court of Justice noted in the 2012 SAS Institute case that "ideas and principles which underlie [computer program] interfaces are not protected by copyright".[98] In a similar 2021 case, the US Supreme Court permitted the recreation of an API in a transformative product under fair use.[99]

A long-debated subject within the FOSS community is whether open-source licenses are "bare licenses" or contracts.[97] A bare license is a set of conditions under which actions otherwise restricted by IP laws are permitted.[86] Under the bare license interpretation, advocated by the FSF, a case is brought to court by the copyright holder as copyright infringement.[86] Under the contract interpretation, a case can be brought to court by an involved party as a breach of contract.[100] US and French courts have tried cases under both interpretations.[101] Non-profit organizations like FSF and the Software Freedom Conservancy offer to hold the rights to developers' projects to enforce compliance.[96]

Public domain software

Main article: Public-domain software
Spaceships and stars on a round monitor
Early computer programs like the pioneering video game Spacewar! are in the public domain.[102]

When a copyright expires, the work enters the public domain, and is freely available to anyone.[103] Some creative works are not covered by copyright and enter directly into the public domain. In the early history of computing, this applied to software.[11] Early computer software was often given away with hardware.[104] Developed initially at MIT, the pioneering video game Spacewar! was used to market and test the PDP-1 computer.[105]

According to attorney

contracts that offer something but impose no terms.[106][107]

A

disclaim warranty and liability. Anyone using the free software must accept this disclaimer as a condition. Because public domain content is available to everyone, the copyright waiver cannot impose a disclaimer.[103]

Use in proprietary software

Open-source licenses allow other businesses to commercialize covered software.[110] Work released under a permissive license can be incorporated into proprietary software.[111] Permissive licenses permit the addition of new terms, including proprietary ones.[112][113] Proprietary software has heavily integrated open-source code released under the Apache, BSD, and MIT licenses.[114] Open core is a business model where developers release a core piece of software as open source and monetize a product containing it as proprietary software.[115] The strong copyleft GPL is written to prevent distribution within proprietary software.[116][117] Weak copyleft licenses impose specific requirements on derivative works that may allow the covered code to be distributed within proprietary software in certain circumstances.[78]

Cloud computing relies on free and open-source software and avoids the distribution that triggers most licenses. Cloud software is hosted rather than distributed.[118] A vendor hosts the software online, and their end users do not have to download, access, or even know about the code in use.[119] The copyleft GNU Affero General Public License (AGPL) is triggered when covered code is hosted or distributed.[120] Some developers have adopted the AGPL, and others have switched to proprietary licenses with features of open-source licensing.[121] For example, open-core developer Elastic switched from the Apache license to the "source-available" Server Side Public License.[122] Source-available software comes with source code as a reference.[123]

Since 2010, the cloud model has grown in prominence.

strip mining.[124] Cloud computing leader Amazon Web Services has stated they comply with licenses and act in their customers' best interests.[124][125]

See also

Notes

  1. ^ Byfield 2008.
  2. ^ Rosen 2005, p. 22.
  3. ^ Rosen 2005, pp. 22–23.
  4. ^ a b Rosen 2005, p. 15.
  5. ^ "Berne Convention". Wex. Cornell Law School. November 2021.
  6. ^ Fagundes & Perzanowski 2020, p. 529.
  7. ^ Rosen 2005, p. 17.
  8. ^ Rosen 2005, pp. 27–28.
  9. ^ Rosen 2005, pp. 28–29.
  10. ^ Rosen 2005, p. 28.
  11. ^ a b Oman 2018, pp. 641–642.
  12. ^ Williams 2002, ch. 1.
  13. ^ Williams 2002, ch. 7.
  14. ^ a b Williams 2002, ch. 9.
  15. ^ Greenbaum 2016, § I.A.
  16. ^ a b c Maracke 2019, § 2.2.
  17. ^ Carver 2005, pp. 448–450.
  18. ^ Perens 1999, ¶ 16.
  19. ^ Greenbaum 2016, pp. 1302–1303.
  20. ^ Greenbaum 2016, pp. 1304–1305.
  21. ^ Greenbaum 2016, p. 1305.
  22. ^ Fontana 2010, p. 2.
  23. ^ Coleman 2004, "Political Agnosticism".
  24. ^ Raymond 1999, "Memes and Mythmaking".
  25. ^ Meeker 2020, 2:33–3:06.
  26. ^ Raymond 2001, "The Cathedral and the Bazaar".
  27. ^ Brock 2022, § 16.3.4.
  28. ^ Raymond 2001.
  29. ^ Raymond 2001, "The Social Context of Open-Source Software".
  30. ^ Raymond 2001, p. 19.
  31. ^ Onetti & Verma 2009, p. 69.
  32. ^ a b Hammerly, Paquin & Walton 1999.
  33. ^ Smith 2022, § 3.2.
  34. ^ a b Sen, Subramaniam & Nelson 2008, pp. 211–212.
  35. ^ a b Meeker 2020, 16:13.
  36. ^ a b Rosen 2005, pp. 22–24.
  37. ^ Bain & Smith 2022, § 10.4.3.
  38. ^ Bain & Smith 2022, § 10.4.2.
  39. ^ a b Bain & Smith 2022, § 10.4.4.
  40. ^ Chestek 2022, p. 30.
  41. ^ Chestek 2022, pp. 184–185.
  42. ^ Rosen 2005, p. 38.
  43. ^ Joy 2022, p. 986.
  44. ^ Joy 2022, p. 989.
  45. ^ Dastar Corp. v. Twentieth Century Fox Film Corp., 539 U.S. 23, 34 (2003).
  46. ^ Joy 2022, pp. 987–988.
  47. ^ Joy 2022, pp. 1004–1006.
  48. ^ Joy 2022, pp. 979, 1002.
  49. ^ a b Rosen 2005, p. 69.
  50. ^ Rosen 2005, pp. 101–102.
  51. ^ a b Smith 2022, § 3.2.1.1.
  52. ^ OSI 2023.
  53. ^ a b Rosen 2005, pp. 73–90.
  54. ^ OSI 2023, "The MIT License".
  55. ^ Smith 2022, § 3.2.1.2.
  56. ^ Bain & Smith 2022, § 10.4.2.
  57. ^ OSI 2023, "Apache License, Version 2.0".
  58. ^ Bain & Smith 2022, ch. 10.
  59. ^ Bain & Smith 2022, § 10.4.4.
  60. ^ St. Laurent 2004, pp. 38–39.
  61. ^ Ballhausen 2019, p. 86.
  62. ^ Rosen 2005, p. 135.
  63. ^ Rosen 2005, pp. 103–106.
  64. ^ Keats 2010, p. 64.
  65. ^ "Full text of GNU Emacs copying permission notice". 1985.
  66. ^ Keats 2010, pp. 63–67.
  67. ^ Rosen 2005, pp. 103–109.
  68. ^ Meeker 2020, 6:00–7:22.
  69. ^ Joy 2022, pp. 990–992.
  70. ^ Onetti & Verma 2009, p. 71.
  71. ^ St. Laurent 2004, pp. 81–83, 114.
  72. ^ Ballhausen 2019, p. 82.
  73. ^ St. Laurent 2004, pp. 68, 75.
  74. ^ a b Tsai 2008, pp. 564–570.
  75. ^ Hammerly, Paquin & Walton 1999, ¶ 23.
  76. ^ Sen, Subramaniam & Nelson 2008, pp. 212–213.
  77. ^ Rosen 2005, refer to corresponding chapters.
  78. ^ a b c Smith 2022, § 3.3.
  79. ^ Rosen 2005, pp. 243–247.
  80. ^ St. Laurent 2004, pp. 159–163.
  81. ^ See Smith 2022, p. 102 for: Apache License version 2.0 in 2004, GPL version 3 in 2007, LGPL version 3 in 2007, and AGPL version 3 in 2007. See Smith 2022, pp. 95–101 for: MPL version 2.0 in 2012 and EPL version 2 in 2017.
  82. ^ Bernelin 2020, pp. 100, 102.
  83. ^ a b Ombredanne 2020, p. 105.
  84. ^ Ombredanne 2020, p. 106.
  85. ^ a b Ballhausen 2022, § 5.3.
  86. ^ a b c d Smith 2022, § 3.4.1.
  87. Fed. Cir.
    2008).
  88. Welte v. Sitecom (District Court of Munich 2004), No. 21 O 6123/04
    .
  89. ^ Smith 2022, p. 106.
  90. ^ Rosen 2005, p. 137.
  91. ^ Rosen 2005, p. 138.
  92. ^ Rosen 2005, ch. 6.
  93. ^ Meeker 2020, 17:04.
  94. ^ St. Laurent 2004, pp. 158–159.
  95. ^ Ballhausen 2022, p. 127.
  96. ^ a b Ballhausen 2022, § 5.4.
  97. ^ a b Walden 2022, § 1.1.
  98. ^ Smith 2022, § 3.1.3.
  99. ^ Google LLC v. Oracle America, Inc., 593 U.S., 1203 (2021).
  100. ^ Smith 2022, § 3.4.2.
  101. ^ Smith 2022, § 3.4.
  102. ^ Ross 2021, "Spacewar: End of Development".
  103. ^ a b Rosen 2005, p. 36.
  104. ^ Walden 2022, p. 3.
  105. ^ Smith 2019, pp. 55–56.
  106. ^ Rosen 2005, pp. 74–77.
  107. ^ St. Laurent 2004, p. 98.
  108. ^ Fagundes & Perzanowski 2020, p. 524.
  109. ^ Joy 2022, pp. 1008–1010.
  110. ^ Brock 2022, § 16.3.3.
  111. ^ St. Laurent 2004, p. 14.
  112. ^ St. Laurent 2004, p. 22.
  113. ^ Onetti & Verma 2009, p. 81.
  114. ^ St. Laurent 2004, p. 30.
  115. ^ Brock 2022, § 16.4.2.3.
  116. ^ Tsai 2008, p. 550.
  117. ^ St. Laurent 2004, p. 39.
  118. ^ a b Brock 2022, § 16.5.2.
  119. ^ Brock 2022, § 16.4.2.8.
  120. ^ Brock 2022, § 16.4.2.2.
  121. ^ Brock 2022, § 16.5.3.
  122. ^ Brock 2022, § 16.5.3.8.
  123. ^ Kunert 2022.
  124. ^ a b Wakabayashi 2019.
  125. ^ Brock 2022, § 16.5.3.2.

References

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