Open source license litigation
Free and open source software is distributed under a variety of free-software licenses which differ significantly from other kinds of software license. Legal action against these licences involves questions about their validity and enforceability.   

This page lists significant open source license litigation to illustrate the legal system's approach to these licenses.

Open source license copyright litigation

Jacobsen v Katzer (2008)

Jacobsen v Katzer addressed the extent to which a copyright holder of free public use software can control the modification and use of their work by another party.  

Jacobsen made code available for public download under an open source public license, Artistic License 1.0, which Katzer copied into their own commercial software products without recognition of the source of the code. Jacobsen argued that the terms of the license defined the scope what the code could be used for and that any use outside of these restrictions would be a copyright infringement. The license holder here expressly stated the terms upon which the right to modify and distribute the material depended. 

The United States Federal Circuit Court of Appeals established that these license terms are enforceable copyright conditions. Katzer had failed to affix the required copyright notices to the derivative software, which therefore was an infringement of the license. The case established that violations of open source licenses can be treated as copyright claims.

BusyBox litigation (2007-13)

During 2007 to 2009, Software Freedom Law Center (SFLC) filed a series of copyright infringement lawsuits on behalf the principal developers of BusyBox. These lawsuits claimed violations of the GNU General Public License Version 2. 

In September 2007 they filed a lawsuit against Monsoon Multimedia, Inc. alleging that Monsoon had violated the GPL by including BusyBox code in some of their products without releasing the source code. In October 2007, an SFLC press release announced that the lawsuit had been settled with Monsoon agreeing to comply with the GPL and pay a sum of money to the plaintiffs. 

In November 2007 they filed a lawsuit against Xterasys Corporation and High-Gain Antennas, LLC. In December 2007, SFLC announced a settlement; Xterasys agreed to stop shipping infringing products until it published the complete source code for the GPL’d code and to pay an undisclosed sum to the plaintiffs. In December 2007 SFLC filed a lawsuit against Verizon Communications, Inc. alleging that Verizon had violated the GPL by distributing BusyBox in wireless routers bundled with the FiOS fiber optic bandwidth service, without providing corresponding source code. A settlement announced In March 2008, included an agreement to comply with the GPL and an undisclosed sum paid to the plaintiffs.

In December 2009, they filed a lawsuit against 14 companies, including Best Buy, Samsung, and Westinghouse with the same allegations of violation of the GPL. By the end of September 2013, all of the defendant companies had agreed on settlement terms, except for Westinghouse, against whom default judgment was entered.

Free Software Foundation, Inc. v. Cisco Systems, Inc (2009)

This was a lawsuit initiated by the Free Software Foundation (FSF) against Cisco Systems on December 11, 2008 in the United States District Court for the Southern District of New York. The FSF claimed that various products sold by Cisco under the Linksys brand had violated the licensing terms of many programs on which FSF held copyright, including GCC, GNU Binutils, and the GNU C Library. Most of these programs were licensed under the GNU General Public License Version 2, and a few under the GNU Lesser General Public License.

The Software Freedom Law Center acted as the FSF's lawyers in the case, asking the court to enjoin Cisco from further distributing Linksys firmware that contained FSF copyrighted code, and also asked for damages amounting from all profits that Cisco received "from its unlawful acts." The FSF contended that code to which it held the copyright was found in multiple Linksys models, and in the program QuickVPN. 

On May 20, 2009 the parties announced a settlement that included Cisco appointing a director to ensure Linksys products comply with free-software licenses, and Cisco making an undisclosed financial contribution to the FSF.

Open source license as a contract litigation

Artifex Software Inc v Hancom Inc (2017)
Leading on from Jacobsen v Katzer this case, from the United States District Court, N.D. California, focused on the breaches of open source software licenses, but extended to contract breaches as well as copyright infringements. Artifex is the exclusive licensor of the software product, ‘Ghostscript’, under the GNU General Public License Version 3. Hancom is a South Korean software company that used Ghostscript in software they were selling. 

This case concerned Hancom's failure to distribute or offer to provide the source code for their software. The GNU GPL provides that the Ghostscript user agrees to its terms, thus creating a contract, if the user does not obtain a commercial license. Artifex alleged that Hancom did not obtain a commercial license to use Ghostscript, and represented publicly that its use of Ghostscript was licensed under the GNU GPL. These allegations sufficiently plead the existence of a contract. 

This case establishes that the GNU GPL constitutes a contract between the owner of the source code and the person/company that uses that code through the license. This sets the precedent that allows licensors to bring claims of breach of contract where the terms of a license are not complied with.

SCO Group Inc v International Business Machines Corporation (2017)

This was a case decided through the United States Court of Appeals for the Tenth Circuit. It covered a complex contractual matrix with claims made in tort across the contractual duties. In the end it created a stir in the open source community as the claims of ownership over code were disputed. Eben Moglen, the counsel for the Free Software Foundation, released a statement regarding the lawsuit: As to its trade secret claims, which are the only claims actually made in the lawsuit against IBM, there remains the simple fact that SCO has for years distributed copies of the kernel, Linux, as part of GNU/Linux free software systems. [...] There is simply no legal basis on which SCO can claim trade secret liability in others for material it widely and commercially published itself under [the GNU GPL Version 2] that specifically permitted unrestricted copying and distribution. The SCO Group announced on May 14, 2003, that they would no longer distribute Linux. SCO said that it would "continue to support existing SCO Linux and Caldera OpenLinux customers and hold them harmless from any SCO intellectual property issues regarding SCO Linux and Caldera OpenLinux products".

SCO claimed and maintains that any code that was GPL'd was done by employees without proper authorization, and thus the license did not stand legally. This is supported by the fact that for code to be GPL'd, the copyright owner must put a GPL notice before the code, and SCO itself was not the one to add the notices.

Software patenting litigation

Diamond v Diehr (1981), Bilski v Kappos (2010), and Alice Corporation Pty Ltd v CLS Bank International (2014)

These cases decided in the Supreme Court of United States set out the law around what makes an invention patent eligible in reference to computer programs. It was stated that to transform an abstract idea into a patent eligible process requires more than simply stating the idea followed by the words, “apply it”; accordingly simply implementing a program on a computer is not a patentable application. This is because if you take away the computer then all that is left is the abstract idea, which is not a process or another accepted creation, and is therefore not patentable. The only place a patent eligible process is qualified by its implementation by a computer is where it improves an existing technological process. So computer programs cannot be patented, but can be copyrighted. 

The Software Freedom Law Center submitted a brief to the United States Court of Appeals in the Federal Circuit for Alice Corporation v CLS Bank to support the long-standing court precedents limiting patent rights for computer programs. The open source community has an interest in limiting the reach of patent law so that free software development is not impeded upon. The SFLC showed its support for the “machine or transformation” test which only allows patents for computer software processes which include a special purpose apparatus not merely a general purpose computer to execute the program. The Court’s decision reflected the ideas set out in the SFLC submission.

Enfish LLC v Microsoft Corp (2016)

In this case, a software patent was questioned and ruled valid. The ruling was that an invention's ability to run on a general-purpose computer does not preclude it from being patent eligible.

Antitrust litigation

Wallace v. International Business Machines Corp (2006)

This case was decided, at the Court of Appeals for the Seventh Circuit, that in United States law the GNU GPL Version 2 did not contravene federal antitrust laws. This suit came after the dismissed action, Wallace v Free Software Foundation (2006), where the Foundation and the GPL Version 2 specifically came under fire for price fixing. Wallace’s argument was that the ‘copyleft’ system created by the Free Software Foundation is a project with IBM, Novell and Red Hat to undercut the prices of potential rivals. It was argued that this could be governed under antitrust law which regulates predatory pricing. The effect would be to shut down a process where a company or companies undercut the competition to gain a monopoly, and then exploit it by raising the prices. 

The purpose of the law is to protect consumers from this process, to promote rivalry to keep prices low. However, Mr. Wallace was attempting to use anti-trust law to drive prices up, suggesting that it was impossible to compete with their prices. Wallace had to prove not only an injury to himself but to the market as well under antitrust law, which he failed to do. 

The claim was quickly dismissed as the number of proprietary operating systems was growing, and there continues to be competition in the market despite some being free of charge. So it was confirmed that the GPL and open source software cannot be challenged by antitrust laws.

Open source software fair use litigation

Oracle America Inc v. Google Inc (2018) 

This was a case finally decided in the United States Federal Circuit Court of Appeals in 2018, which concerned the fair use by Google of the source code licensed by Oracle under the GNU GPL Version 2. Google had copied 37 Application Programming Interface packages (APIs) to aid in the building of its free Android software for smartphones. Google had taken these APIs and then written its own implementing code and launched a product which competed with Oracle’s. 

The conditions of the license were that the improvements of the code, or derivative code, had to be shared for free use. If somebody wanted to avoid this, but still use the APIs, or where they would be competing with the owners of the code, then they would need to pay a licensing fee. Google used the APIs without paying a licensing fee, but competed with Oracle’s product, which Oracle contended was a breach of copyright. 

The Court of Appeals decided in favor of Oracle, after considering what would make a fair use of the code, with Google failing on a majority of accounts. As of November 15, 2019, the United States Supreme Court has decided to allow appeal to its court on the same question, which now holds $9 billion in damages above Google if they fail again.

In April 2021, the Supreme Court ruled in a 6–2 decision that Google's use of the Java APIs fell within the four factors of fair use, bypassing the question on whether APIs can be copyrighted. The decision reversed the Federal Circuit ruling and remanded the case for further review.

Open source software trade secrets litigation
A Korean case (2005) from the Seoul Central District Court in September, 2005 considered the issue of defendants conducting business for a rival company using source code from a program developed by the company they had previously worked, licensed under a GNU GPL Version 2. Trade secrets are sufficient if their contents are of competitive property value and, unlike patents, are not required to be novel or progressive. The purpose of prohibiting trade secret infringement is to avoid unfair advantage, stopping companies from obtaining a favorable head-start over competitors placing them in a superior position. 

One defendant retired from their company and kept a copy of the source code privately, providing it to the rival company, shortening the development period by two months. The Court ruled that the GPL was not material to the case. The Defendants argued that it is impossible to maintain trade secrets while being compliant with GPL and distributing the work, so they could not be in breach of trade secrets. This argument was considered without ground and the defendants were sentenced following criminal proceedings.

Other/international open source license litigation

Planetary Motion v. Techsplosion (2001)
United States Court of Appeals, Eleventh Circuit case, “Software distributed pursuant to [the GPL] is not necessarily ceded to the public domain” (dicta).

Computer Associates v. Quest (2004)
This case decided in the United States District Court, N.D. Illinois, Eastern Division considered the fact that Computer Associate’s source code contains previously known source code (GNU Bison Version 1.25), available under the GPL, does not prevent them from protecting their own source code. There is a special exception in the GPL to allow the use of output files without the usual restrictions for versions of Bison after and including version 1.25.

Welte v. Sitecom Germany (2004)

In April 2004 a preliminary injunction against Sitecom Germany was granted by Munich District Court after Sitecom refused to cease distribution of Netfilter's GPL'ed software in violation of the terms of the GPL Version 2. The court's justification was:Defendant has infringed on the copyright of plaintiff by offering the software 'netfilter/iptables' for download and by advertising its distribution, without adhering to the license conditions of the GPL. Said actions would only be permissible if defendant had a license grant.

Welte v. D-Link (2006) 
On 6 September 2006 in the District Court of Frankfurt, the gpl-violations.org project prevailed in court litigation against D-Link Germany GmbH regarding D-Link's copyright-infringing use of parts of the Linux Kernel in devices they distributed. The judgment stated that the GPL is valid, legally binding, and stands in German court.

AFPA v. Edu4 (2009)
September 22, 2009 the Paris Court of Appeals made ruled that the company Edu4 violated the terms of the GNU GPL Version 2 when it distributed binary copies of the remote desktop access software VNC but denied users access to its corresponding source code. Olivier Hugot, attorney of Free Software Foundation France said:Companies distributing the software have been given a strong reminder that the license's terms are enforceable under French law. And users in France can rest assured that, if need be, they can avail themselves of the legal system to see violations addressed and their rights respected...But what makes this ruling unique is the fact that the suit was filed by a user of the software, instead of a copyright holder. It's a commonly held belief that only the copyright holder of a work can enforce the license's terms - but that's not true in France. People who received software under the GNU GPL can also request compliance, since the license grants them rights from the authors.

Free/Iliad (2011)
This was an October 2008 case from Paris Regional Court (Tribunal de Grande Instance de Paris). Free/Illiad is an ISP; the routers they distribute contains software under GPL Version 2, but Free/Iliad didn't provide the source code nor the GPL text. 

Free/Illiad's argument was that the routers are their property (not sold to customers) and still on their network, which would not amount to "distribution" in the terms of the GPL. A secret extra-judicial agreement was reached in July 2011. Free has since released the source code and informed users of the GPL software in their routers.

China's courts rulings on open-source licensing (2018)
The Beijing Intellectual Property Court (BIPC) saw a case from business-software developer Digital Heaven claiming that software developer YouZi had copied the code for three plug-ins contained in its development tool "Hbuilder". The court found in 2018 that YouZi violated copyright, this decision proving to be controversial as the legal test employed by the court differed from the reasoning used by the United States courts. 

YouZi argued that since Hbuilder is based on a GNU open-source module known as "Aptana", which is licensed under General Public Licence Version 3; HBuilder is also open source software with source code anybody should be entitled to use. The BIPC decided it was only necessary to identify whether the three specific plug-ins used by YouZi are subject to the GPL. The Aptana-GPL Exception License stipulates that the works which are identifiable sections of the modified version and can be seen as independent works, would not fall under the GPL. Without further examination of the open source licences, the court ruled the GPL did not apply to the three plug-ins and therefore Hbuilder could not be considered a derivative work licensed under the GPL.

References

Free and open-source software
Litigation by party