Software copyright

Last updated

Software copyright is the application of copyright in law to machine-readable software. While many of the legal principles and policy debates concerning software copyright have close parallels in other domains of copyright law, there are a number of distinctive issues that arise with software. This article primarily focuses on topics particular to software.

Contents

Software copyright is used by software developers and proprietary software companies to prevent the unauthorized copying of their software. Free and open source licenses also rely on copyright law to enforce their terms. For instance, copyleft licenses impose a duty on licensees to share their modifications to the work with the user or copy owner under some circumstances. No such duty would apply had the software in question been in the public domain.

National and supranational laws

Canada

In Canada, software is protected as a literary work under the Copyright Act of Canada. Copyright is acquired automatically when an original work is generated; the creator is not required to register or mark the work with the copyright symbol in order to be protected. [1] The rights holder is granted: the exclusive right of reproduction, the right to rent the software, the right to restrain others from renting the software and the right to assign or license the copyright to others. Exceptions to these rights are set out by the terms of Fair Dealing; these exempt users from copyright liability covering usage and reproduction when performed for research, private study, education, parody or satire. [2] Changes to the Copyright Act in regard to digital copyright were debated in the Canadian Parliament in 2008. Bill C-61 proposed alterations of the breadth and depth of exemptions for uses such as personal back-ups, reverse engineering and security testing.

China

Software copyright in China in Chinese Law means that a creator or other Obligee enjoys exclusive rights of the software under related copyright law.

It is a civil right and has the common features of all other civil rights. It is an exception in intellectual property rights because it is owned without individual confirmation. This is usually referred to as the principle of “automatic protection”. The owner enjoys the right of publication, authorship, consent to use as well as the right of being paid.

East Germany

A 1979 East German court ruling found that software was "neither a scientific work nor a creative achievement" and ineligible for copyright protection, legalizing software copying in the country. [3]

European Union

India

Software can be copyrighted in India. [4] Copyright in software, in the absence of any agreement to the contrary, vests in the author of the software, even for commissioned works. Copyright can be assigned or licensed through a written document, but under the Indian Copyright Act, in case the period of assignment is not specified, the period is deemed to be 5 years from the date of assignment (section 19(5) of the Copyright Act). In a recent judgement in the case of Pine Labs Private Limited v. Gemalto Terminals India Private Limited [5] the Delhi High Court has laid down that the copyright belongs to the author (in this case, Pine Labs) and as the period of assignment was not specified in the document of assignment (the master service agreement), the copyright in the software reverted to Pine Labs after 5 years. See Assignment of Copyright in Software.

Pakistan

Under the provision of Copyright Ordinance 1962, works which fall into any of the following categories: literary, musical, or artistic are protected by Copyright law. The definition of literary work was amended by Copyright Amendment 1992 to include computer software. Section 2(p) of the ordinance defines a computer program as "that is to say programmes recorded on any disc, tape, perforated media or other information storage devices, which, if fed into or located in a computer or computer based equipment is capable of reproducing any information". [6] In event of infringement, civil and/or criminal proceedings can be carried out. According to Chapter XIV of Copyright Ordinance, a person can face a prison of up to 3 years and/or a penalty of up to one hundred thousand rupees if he is found guilty of renting computer software without permission of the owner. [7] According to a study of Business Software Alliance, 84% of software in Pakistan is being used in violation of the Copyright law of Pakistan. [8]

United States

Copyright protection attaches to “original works of authorship fixed in any tangible medium of expression, now known or later developed, from which they can be perceived, reproduced, or otherwise communicated, either directly or with the aid of a machine or device.” (17 U.S.C.A. § 102). Copyright functions by granting the author the right to exclude others. Copyright protects:

+ compilations and derivative works  17 USC § 103(a).

In the United States, computer programs are literary works, under the definition in the Copyright Act, 17 U.S.C.   § 101. [9]

There is a certain amount of work that goes into making copyright successful and just as with other works, copyright for computer programs prohibits not only literal copying, but also copying of "nonliteral elements", such as program's structure, sequence and organization. These non-literal aspects, however, can be protected only "to the extent that they incorporate authorship in programmer's expression of original ideas, as distinguished from the ideas themselves." [10] In Computer Associates vs Altai , the Second Circuit proposed the Abstraction-Filtration-Comparison test for identifying these protected elements. This test attempts to distinguish copyrightable aspects of a program from the purely utilitarian and the public domain.

Copyright attaches only to original works. A work is “created” when it is fixed in a “tangible medium of expression” for the first time. 17 U.S.C. § 101. Circuits differ on what it means for a work to be fixed for the purposes of copyright law and infringement analysis. The graphics, sounds, and appearance of a computer program also may be protected as an audiovisual work; as a result, a program can infringe even if no code was copied. [11] The set of operations available through the interface is not copyrightable in the United States under Lotus v. Borland , but it can be protected with a utility patent. The law is unclear as to whether transient copies  such as those cached when transmitting digital content, or temporary copies in a computer's RAM   are “fixed” for the purposes of copyright law. [12] The Ninth Circuit has held that “A derivative work must be fixed to be protected under the Act, but not to infringe.” [13] In Apple v. Microsoft , the courts established that a look and feel copyright claim must demonstrate that specific elements of a user interface infringe on another work. A program's particular combination of user interface elements is not copyrightable.

History

Historically, computer programs were not effectively protected by copyrights because computer programs were not viewed as a fixed, tangible object: object code was viewed as a utilitarian good produced from source code rather than as a creative work. Due to lack of precedent, this outcome was reached while deciding how to handle copyright of computer programs. The Copyright Office attempted to classify computer programs by drawing an analogy: the blueprints of a bridge and the resulting bridge compared to the source code of a program and the resulting executable object code. [14] This analogy caused the Copyright Office to issue copyright certificates under its Rule of Doubt.

In 1974, the Commission on New Technological Uses of Copyrighted Works (CONTU) was established. CONTU decided that "computer programs, to the extent that they embody an author's original creation, are proper subject matter of copyright." [15] [14] In 1980, the United States Congress added the definition of "computer program" to 17 U.S.C.   § 101 and amended 17 U.S.C.   § 117 to allow the owner of the program to make another copy or adaptation for use on a computer. [16]

This legislation, plus court decisions such as Apple v. Franklin in 1983 clarified that the Copyright Act gave computer programs the copyright status of literary works. Many companies began to claim that they "licensed" but did not sell their products, in order to avoid the transfer of rights to the end-user via the doctrine of first sale (see Step-Saver Data Systems, Inc. v. Wyse Technology ). These software license agreements are often labeled as end-user license agreements (EULAs). Another impact of the decision was the rise of the shrink-wrap closed source business model, where before a source code driven software distribution schema dominated. [15] [17]

In 1998, The United States Congress passed the Digital Millennium Copyright Act (DMCA) which criminalizes evasion of copy protection (with certain exceptions), destruction or mismanagement of copyright management information, but includes a clause to exempt ISPs from liability of infringement if one of their subscribers infringes. In addition, the DMCA extends protection to those who copy a program for maintenance, repair or backup as long as these copies are "destroyed in the event that continued possession of the computer program should cease to be rightful."17 U.S.C.   § 117

EULAs and rights of end users

The Copyright Act expressly permits copies of a work to be made in some circumstances, even without the authorization of the copyright holder. In particular, "owners of copies" may make additional copies for archival purposes, "as an essential step in the utilization of the computer program", or for maintenance purposes. [18] Furthermore, "owners of copies" have the right to resell their copies, under the first sale doctrine and 17 U.S.C.   § 109.

These rights only apply to "owners of copies." Most software vendors claim that their products are "licensed, not sold", [19] thus sidestepping 17 U.S.C.   § 117. American courts have taken varying approaches when confronted with these software license agreements. In MAI Systems Corp. v. Peak Computer, Inc. , Triad Systems Corp. v. Southeastern Express Co. , and Microsoft v Harmony, [20] various Federal courts held that "licensed, not sold" language in an EULA was effective. Other courts have held that "no bright-line rule distinguishes mere licenses from sales...The label placed on a transaction is not determinative". [21] The Ninth Circuit took a similar view (in the specialized context of bankruptcy) in Microsoft Corp. v. DAK Industries, Inc. [22]

By contrast, in the European Union the European Court of Justice held that a copyright holder cannot oppose the resale of a digitally sold software, in accordance with the rule of copyright exhaustion on first sale as ownership is transferred, and questions therefore the "licensed, not sold" EULAs in the EU. [23] [24] [25] [26] [27] [28]

Fair use

Fair use is a defense to an allegation of copyright infringement under section 107 of the Copyright Act of 1976. This section describes some of the uses of copyrighted software that courts have held to be fair.

In Galoob v. Nintendo , the 9th Circuit held that modification of copyrighted software for personal use was fair. In Sega v. Accolade , the 9th Circuit held that making copies in the course of reverse engineering is a fair use, when it is the only way to get access to the "ideas and functional elements" in the copyrighted code, and when "there is a legitimate reason for seeking such access".

The Supreme Court ruled in Google LLC v. Oracle America, Inc. (2021) that the reuse of application programming interfaces (APIs) including representative source code can be transformative and fall within fair use, though did not rule if such APIs are copyrightable. [29]

Copyleft

A copyleft is a type of copyright license that allows redistributing the work (with or without changes) on condition that recipients are also granted these rights. [30] [31]

See also

Related Research Articles

Fair use is a doctrine in United States law that permits limited use of copyrighted material without having to first acquire permission from the copyright holder. Fair use is one of the limitations to copyright intended to balance the interests of copyright holders with the public interest in the wider distribution and use of creative works by allowing as a defense to copyright infringement claims certain limited uses that might otherwise be considered infringement. Unlike "fair dealing" rights that exist in most countries with a British legal history, the fair use right is a general exception that applies to all different kinds of uses with all types of works and turns on a flexible proportionality test that examines the purpose of the use, the amount used, and the impact on the market of the original work.

The idea–expression distinction or idea–expression dichotomy is a legal doctrine in the United States that limits the scope of copyright protection by differentiating an idea from the expression or manifestation of that idea.

The first-sale doctrine is an American legal concept that limits the rights of an intellectual property owner to control resale of products embodying its intellectual property. The doctrine enables the distribution chain of copyrighted products, library lending, giving, video rentals and secondary markets for copyrighted works. In trademark law, this same doctrine enables reselling of trademarked products after the trademark holder puts the products on the market. In the case of patented products, the doctrine allows resale of patented products without any control from the patent holder. The first sale doctrine does not apply to patented processes, which are instead governed by the patent exhaustion doctrine.

Copyright misuse is an equitable defence to copyright infringement in the United States based upon the doctrine of unclean hands. The misuse doctrine provides that the copyright holder engaged in abusive or improper conduct in exploiting or enforcing the copyright will be precluded from enforcing his rights against the infringer. Copyright misuse is often comparable to and draws from the older and more established doctrine of patent misuse, which bars a patentee from obtaining relief for infringement when he extends his patent rights beyond the limited monopoly conferred by the law.

A software license is a legal instrument governing the use or redistribution of software. Under United States copyright law, all software is copyright protected, in both source code and object code forms, unless that software was developed by the United States Government, in which case it cannot be copyrighted. Authors of copyrighted software can donate their software to the public domain, in which case it is also not covered by copyright and, as a result, cannot be licensed.

Anti-circumvention refers to laws which prohibit the circumvention of technological barriers for using a digital good in certain ways which the rightsholders do not wish to allow. The requirement for anti-circumvention laws was globalized in 1996 with the creation of the World Intellectual Property Organization's Copyright Treaty.

White-Smith Music Publishing Company v. Apollo Company, 209 U.S. 1 (1908), was a decision by the Supreme Court of the United States which ruled that manufacturers of music rolls for player pianos did not have to pay royalties to the composers. The ruling was based on a holding that the piano rolls were not copies of the plaintiffs' copyrighted sheet music, but were instead parts of the machine that reproduced the music.

<i>Computer Associates International, Inc. v. Altai, Inc.</i> American legal case

Computer Associates International, Inc. v. Altai, Inc., 982 F.2d 693 is a decision from the United States Court of Appeals for the Second Circuit that addressed to what extent non-literal elements of software are protected by copyright law. The court used and recommended a three-step process called the Abstraction-Filtration-Comparison test. The case was an appeal from the United States District Court for the Eastern District of New York in which the district court found that defendant Altai's OSCAR 3.4 computer program had infringed plaintiff Computer Associates' copyrighted computer program entitled CA-SCHEDULER. The district court also found that Altai's OSCAR 3.5 program was not substantially similar to a portion of CA-SCHEDULER 7.0 called SYSTEM ADAPTER, and thus denied relief as to OSCAR 3.5. Finally, the district court concluded that Computer Associates' state law trade secret misappropriation claim against Altai was preempted by the federal Copyright Act. The appeal was heard by Judges Frank Altimari, John Daniel Mahoney, and John M. Walker, Jr. The majority opinion was written by Judge Walker. Judge Altimari concurred in part and dissented in part. The Second Circuit affirmed the district court's ruling as to copyright infringement, but vacated and remanded its holding on trade secret preemption.

<i>Vault Corp. v. Quaid Software Ltd.</i> U.S. legal case

Vault Corporation v Quaid Software Ltd. 847 F.2d 255 is a case heard by the United States Court of Appeals for the Fifth Circuit that tested the extent of software copyright. The court held that making RAM copies as an essential step in utilizing software was permissible under §117 of the Copyright Act even if they are used for a purpose that the copyright holder did not intend. It also applied the "substantial noninfringing uses" test from Sony Corp. of America v. Universal City Studios, Inc. to hold that Quaid's software, which defeated Vault's copy protection mechanism, did not make Quaid liable for contributory infringement. It held that Quaid's software was not a derivative work of Vault's software, despite having approximately 30 characters of source code in common. Finally, it held that the Louisiana Software License Enforcement Act clause permitting a copyright holder to prohibit software decompilation or disassembly was preempted by the Copyright Act, and was therefore unenforceable.

<span class="mw-page-title-main">Derivative work</span> Expressive work created from a major part of a different, original artwork

In copyright law, a derivative work is an expressive creation that includes major copyrightable elements of an original, previously created first work. The derivative work becomes a second, separate work independent in form from the first. The transformation, modification or adaptation of the work must be substantial and bear its author's personality sufficiently to be original and thus protected by copyright. Translations, cinematic adaptations and musical arrangements are common types of derivative works.

The copyright law of the United States grants monopoly protection for "original works of authorship". With the stated purpose to promote art and culture, copyright law assigns a set of exclusive rights to authors: to make and sell copies of their works, to create derivative works, and to perform or display their works publicly. These exclusive rights are subject to a time limit, and generally expire 70 years after the author's death or 95 years after publication. In the United States, works published before January 1, 1928, are in the public domain.

<span class="mw-page-title-main">Copyright infringement</span> Usage of a copyrighted work without the authors permission

Copyright infringement is the use of works protected by copyright without permission for a usage where such permission is required, thereby infringing certain exclusive rights granted to the copyright holder, such as the right to reproduce, distribute, display or perform the protected work, or to make derivative works. The copyright holder is typically the work's creator, or a publisher or other business to whom copyright has been assigned. Copyright holders routinely invoke legal and technological measures to prevent and penalize copyright infringement.

<span class="mw-page-title-main">Digital Millennium Copyright Act</span> United States copyright law

The Digital Millennium Copyright Act (DMCA) is a 1998 United States copyright law that implements two 1996 treaties of the World Intellectual Property Organization (WIPO). It criminalizes production and dissemination of technology, devices, or services intended to circumvent measures that control access to copyrighted works. It also criminalizes the act of circumventing an access control, whether or not there is actual infringement of copyright itself. In addition, the DMCA heightens the penalties for copyright infringement on the Internet. Passed on October 12, 1998, by a unanimous vote in the United States Senate and signed into law by President Bill Clinton on October 28, 1998, the DMCA amended Title 17 of the United States Code to extend the reach of copyright, while limiting the liability of the providers of online services for copyright infringement by their users.

<i>Sega v. Accolade</i> 1992 American court case

Sega Enterprises Ltd. v. Accolade, Inc., 977 F.2d 1510, is a case in which the United States Court of Appeals for the Ninth Circuit applied American intellectual property law to the reverse engineering of computer software. Stemming from the publishing of several Sega Genesis games by video game publisher Accolade, which had disassembled Genesis software in order to publish games without being licensed by Sega, the case involved several overlapping issues, including the scope of copyright, permissible uses for trademarks, and the scope of the fair use doctrine for computer code.

<i>MDY Industries, LLC v. Blizzard Entertainment, Inc.</i> Court case in the United States

MDY Industries, LLC v. Blizzard Entertainment, Inc and Vivendi Games, Inc., 629 F.3d 928, is a case decided by the United States Court of Appeals for the Ninth Circuit. At the district court level, MDY had been found liable under theories of copyright and tort law for selling software that contributed to the breach of Blizzard's End User License Agreement (EULA) and Terms of Use (ToU) governing the World of Warcraft video game software.
The court's ruling was appealed to the United States Court of Appeals for the Ninth Circuit, which reversed the district court in part, upheld in part, and remanded for further proceedings. The Court of Appeals ruled that for a software licensee's violation of a contract to constitute copyright infringement, there must be a nexus between the license condition and the licensor’s exclusive rights of copyright. However, the court also ruled, contrary to Chamberlain v. Skylink, that a finding of circumvention under the Digital Millennium Copyright Act does not require a nexus between circumvention and actual copyright infringement.

<i>Vernor v. Autodesk, Inc.</i> United States district court case

Vernor v. Autodesk, Inc. was a case in the United States District Court for the Western District of Washington regarding the applicability of the first-sale doctrine to software sold under the terms of so-called "shrinkwrap licensing." The court held that when the transfer of software to the purchaser materially resembled a sale it was, in fact, a "sale with restrictions on use" giving rise to a right to resell the copy under the first-sale doctrine. As such, Autodesk could not pursue an action for copyright infringement against Vernor, who sought to resell used versions of its software on eBay. The decision was appealed to the United States Court of Appeals for the Ninth Circuit, which issued a decision on September 10, 2010, reversing the first-sale doctrine ruling and remanding for further proceedings on the misuse of copyright claim. The Ninth Circuit's decision asserted that its ruling was compelled by Ninth Circuit precedent, but observed that the policy considerations involved in the case might affect motion pictures and libraries as well as sales of used software.

<i>Bowers v. Baystate Technologies, Inc.</i>

Bowers v. Baystate Technologies, 320 F.3d 1317, was a U.S. Court of Appeals Federal Circuit case involving Harold L. Bowers and Baystate Technologies over patent infringement, copyright infringement, and breach of contract. In the case, the court found that Baystate had breached their contract by reverse engineering Bower's program, something expressly prohibited by a shrink wrap license that Baystate entered into upon purchasing a copy of Bower's software. This case is notable for establishing that license agreements can preempt fair use rights as well as expand the rights of copyright holders beyond those codified in US federal law.

<i>Capitol Records, LLC v. ReDigi Inc.</i>

Capitol Records, LLC v. ReDigi Inc., 934 F. Supp. 2d 640 , is a case from the United States District Court for the Southern District of New York concerning copyright infringement of digital music. In ReDigi, record label Capitol Records claimed copyright infringement against ReDigi, a service that allows resale of digital music tracks originally purchased from the iTunes Store. Capitol Records' motion for a preliminary injunction against ReDigi was denied, and oral arguments were given on October 5, 2012.

Navitaire Inc v Easyjet Airline Co. and BulletProof Technologies, Inc., is a decision by the England and Wales High Court of Justice. The case involved a copyright infringement claim brought by Navitaire Inc. ("Navitaire") against EasyJet Airline Company ("EasyJet") and Bulletproof Technologies, Inc. ("Bulletproof") with regards to software used to construct an airline booking system. Curiously, it was not claimed that Defendant had access to the original source code or that Defendant's source code resembled Plaintiff's in any way.

The protection of intellectual property (IP) of video games through copyright, patents, and trademarks, shares similar issues with the copyrightability of software as a relatively new area of IP law. The video game industry itself is built on the nature of reusing game concepts from prior games to create new gameplay styles but bounded by illegally direct cloning of existing games, and has made defining intellectual property protections difficult since it is not a fixed medium.

References

  1. "Do I need to mark my work with the copyright symbol? - Canadian Intellectual Property Office". Archived from the original on 2013-05-13. Retrieved 2012-12-13.
  2. "Consolidated federal laws of canada, Copyright Act". July 2020.
  3. Gießler, Denis (2018-11-21). "Video Games In East Germany: The Stasi Played Along". Die Zeit (in German). Retrieved 2018-11-30.
  4. "Linux News: Tech Buzz: Only in America? Copyright Law Key to Global Free Software Model". Linuxinsider.com. Retrieved 2011-10-29.
  5. "Judgment in the case of Pine Labs Private Limited vs Gemalto Terminals India Private Limited and others (FAO 635 of 2009 and FAO 636 of 2009)" (PDF). lobis.nic.in. 2011-08-03. Archived from the original (PDF) on 2012-02-01. Retrieved 2011-10-29.
  6. COPYRIGHT FOR COMPUTER PROGRAMMES IN PAKISTAN
  7. The Copyright Ordinance of Pakistan 1962, Chapter XIV (PDF), archived from the original (PDF) on 2014-06-29
  8. Global Study of Business Software Alliance (PDF)
  9. Apple v Franklin, 714 F.2d 1240 (3d Cir. 1983)
  10. Computer Assocs. Int'l v. Altai, Inc., 982 F.2d 693 (2d Cir. 1992)
  11. Stern Elecs., Inc. v. Kaufman, 669 F.2d 852, 855 (2d Cir.1982)
  12. 17 U.S.C. § 101. Compare Cartoon Network LP v. CSC Holdings, Inc., 536 F.3d 121, 127 (2nd Cir. 2008).
  13. Lewis Galoob Toys, Inc. v. Nintendo of Am., Inc., 964 F.2d 965, 968 (9th Cir. 1992).
  14. 1 2 Lemley, Menell, Merges and Samuelson. Software and Internet Law, p. 34
  15. 1 2 Apple Computer, Inc. v. Franklin Computer Corporation Puts the Byte Back into Copyright Protection for Computer Programs in Golden Gate University Law Review Volume 14, Issue 2, Article 3 by Jan L. Nussbaum (January 1984)
  16. Lemley, Menell, Merges and Samuelson. Software and Internet Law, p. 35
  17. Landley, Rob (2009-05-23). "notes-2009". landley.net. Retrieved 2015-12-02. So if open source used to be the norm back in the 1960s and 70s, how did this _change_? Where did proprietary software come from, and when, and how? How did Richard Stallman's little utopia at the MIT AI lab crumble and force him out into the wilderness to try to rebuild it? Two things changed in the early 80s: the exponentially growing installed base of microcomputer hardware reached critical mass around 1980, and a legal decision altered copyright law to cover binaries in 1983.
  18. 17 U.S.C.   § 117
  19. Walker, John (2012-02-01). "Thought: Do We Own Our Steam Games?". Rock, Paper, Shotgun . Retrieved 2014-12-27. I asked gamer lawyer Jas Purewal about this a short while back, not specifically about Valve, and he explained that the matter is still unresolved. "In fact," he says, "it's never been completely resolved for software generally[...]"
  20. Microsoft Corp. v. Harmony Computers & Elecs., Inc., 846 F. Supp. 208 (E.D.N.Y. 1994)
  21. Vernor v. Autodesk, Inc., 555 F.Supp.2d 1164 (W.D.Wash. 2008).
  22. Microsoft Corp. v. DAK Indus., Inc., 66 F.3d 1091 (9th Cir. 1995)
  23. Purewal, Jas. "The legality of second hand software sales in the EU". gamerlaw.co.uk. (mirror on gamasutra.com)
  24. hg/mz (AFP, dpa) (2012-07-03). "Oracle loses court fight over software resale rules". dw.de . Retrieved 2014-12-30. A European court has ruled that it's permissible to resell software licenses even if the package has been downloaded directly from the Internet. It sided with a German firm in its legal battle with US giant Oracle.
  25. Voakes, Greg (2012-07-03). "European Courts Rule In Favor Of Consumers Reselling Downloaded Games". forbes.com . Retrieved 2014-12-30. Could this be the victory we need for a "gamer's bill of rights" ? DRM is an oft-cited acronym, and resonates negatively in the gaming community. The Court of Justice of the European Union ruled in favor of reselling downloaded games. Simply put, legally purchased and downloaded games will be treated like physical copies of the game, and consumers can then sell their 'used' game.
  26. "JUDGMENT OF THE COURT (Grand Chamber)". InfoCuria – Case-law of the Court of Justice. 2012-07-03. Retrieved 2014-12-30. (Legal protection of computer programs — Marketing of used licences for computer programs downloaded from the internet — Directive 2009/24/EC — Articles 4(2) and 5(1) — Exhaustion of the distribution right — Concept of lawful acquirer)
  27. Timothy B. Lee (2012-07-03). "Top EU court upholds right to resell downloaded software". Ars Technica.
  28. "EU Court OKs Resale of Software Licenses". AP.
  29. Fung, Brian (April 5, 2021). "Supreme Court hands Google a victory in a multibillion-dollar case against Oracle". CNN . Retrieved April 5, 2021.
  30. "Categories of free and nonfree software". www.gnu.org. Retrieved 2011-10-29.
  31. "What is copyleft?". www.gnu.org. Retrieved 2011-10-29.