The GNU General Public License, often abbreviated as GNU GPL or simply GPL, is a set of highly popular free software licenses that ensure end users enjoy four fundamental freedoms when using software: the freedom to run it, study its source code, share it, and modify it.

This license marked a significant milestone as the first general-purpose copyleft license, initially authored by Richard Stallman, the founder of the Free Software Foundation (FSF), for the GNU Project.

The GPL provides recipients of a computer program with rights in accordance with the Free Software Definition.

All licenses within the GPL series are considered copyleft licenses, which means that any derivative work must be distributed under the same or equivalent licensing terms.

It is notably more restrictive than the Lesser General Public License and significantly differs from the more widely used permissive software licenses such as BSD, MIT, and Apache licenses.

This article revolves around copyright GPL and will provide you a valuable information regarding this.


Most software licenses are crafted to limit your ability to share and modify the software.

In contrast, the GNU GPL is specifically designed to safeguard your freedom to both share and modify free software, ensuring that it remains freely accessible to all users.

This license is applicable to a majority of the Free Software Foundation’s software, as well as any other programs whose creators choose to adopt it. (Certain other Free Software Foundation software is governed by the GNU Lesser General Public License.)

You also have the option to apply this license to your own software programs.

Terms and Conditions

The terms and conditions of the GNU General Public License (GPL) must be accessible to anyone who receives a copy of a work covered by the GPL (“the licensee”).

Licensees who adhere to these terms and conditions are granted the authorisation to alter, replicate, and disseminate the work or any derived variations.

The licensee is also permitted to charge a fee for these services or provide them free of charge.

The GPL differs from software licenses that forbid distribution for commercial objectives due to this feature.

In Version 3 of the license, compliance with the seventh section can also be achieved by offering the source code through alternative means.

These methods encompass downloading the source code from an adjacent network server or via peer-to-peer transmission, as long as these methods align with how the compiled code was originally accessible, and there are clear instructions regarding where to locate the source code.

The Free Software Foundation advocates for the absence of commercial usage restrictions on free software, and the GPL explicitly permits the sale of works licensed under GPL at any price.

Remember that unless an author specifically assigns their copyrights to the FSF, the FSF does not possess the copyright for a work released under the GPL.

This is uncommon, except for programs that are affiliated with the GNU project.

Copyright holders have the option of pursuing legal action if there is suspicion of a license violation.

Usage of Licensed Software

Software released under the GNU General Public License (GPL) can be employed for a wide range of purposes, including commercial use and even as a tool for creating proprietary software, as is the case when using compilers licensed under the GPL.

Individuals or organisations that distribute software covered by the GPL, such as applications, have the flexibility to either charge a fee for copies or provide them for free.

The GPL differs from shareware software licenses since it permits personal copying but limits commercial distribution. It also differs from proprietary licenses because they forbid copying owing to copyright laws.

According to the Free Software Foundation (FSF), freely distributable software that supports user autonomy shouldn’t obstruct redistribution or commercial use.

When the software is used exclusively for private or internal purposes, with no sales or distribution involved, individuals can modify the software code and reuse parts of it without the obligation to release the source code.

However, in cases involving sales or distribution, the complete source code must be made available to end users, encompassing any alterations or additions to the code.

In such instances, copyleft is applied to ensure that end users retain the freedoms outlined above.

Nonetheless, software that functions as an application program within an operating system licensed under the GPL, such as Linux, is not mandated to be licensed under the GPL or distributed with source code availability.

The licensing hinges solely on the libraries and software components used, and it is not influenced by the underlying platform.

For instance, if a program comprises exclusively original source code or is combined with source code from other software components, then the custom software components are not obligated to be licensed under the GPL or to release their source code.

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Even if the underlying operating system is GPL-licensed, applications running on it are not regarded as derivative works.


The distribution rights granted by the GNU General Public License (GPL) for modified versions of a work come with certain conditions.

The conditions for releasing the whole piece of work cannot be more stringent than those outlined in the GPL when someone publishes a GPL-protected work combined with their own alterations.

This requirement is known as copyleft, and it derives its legal strength from the application of copyright to software programs.

Because a GPL-licensed work is protected by copyright, a licensee does not have the right to redistribute it, even in a modified form (except for situations covered by fair use), unless they adhere to the terms of the license.

Essentially, one must comply with the GPL if one wants to exercise rights that are typically restricted by copyright law, such as the right to redistribute.

On the other hand, if someone shares copies of the work without adhering to the GPL’s terms (such as by keeping the source code confidential), the original author has the right to pursue legal action under copyright law.

Historically, copyright law has been employed to prevent unauthorised distribution of works.

Copyleft, in contrast, employs copyright laws to achieve a distinct purpose.

It gives all parties distribution rights as long as they also transfer the same rights to succeeding parties, and so on.

This is how the GPL and other copyleft licenses aim to ensure open access to the work and all its derivatives.

Copyleft comes into play exclusively when an individual intends to share the software with others.

Developers can create private, modified versions of the software without any obligation to disclose the modifications, as long as they refrain from distributing the altered software to third parties.

It is necessary to comprehend that copyleft solely applies to the software and does not include its output, unless the output is classified as a derivative work of the software.

For instance, consider a public web portal that runs a modified version of a GPL-licensed content management system.

In this scenario, there is no requirement to distribute the alterations made to the underlying software.

This is because the modified web portal is not being shared but rather hosted. Additionally, the web portal’s output does not qualify as a derivative work of the GPL-licensed content management system.

Suggested Reading: Difference Between Copyleft and Copyright

License vs. Contract Distinction

The GNU General Public License (GPL) was intentionally crafted as a license rather than a contract.

In certain Common Law jurisdictions, the legal differentiation between a license and a contract holds significant importance: contracts are upheld through contract law, whereas licenses fall under the jurisdiction of copyright law.

However, this distinction becomes less relevant in numerous jurisdictions, particularly those operating under Civil Law systems, where there is little to no disparity between contracts and licenses.

If someone chooses not to agree to the terms and conditions of the GPL, they do not have the legal right to copy or distribute software licensed under the GPL or any derived works thereof.

Nevertheless, if they choose not to distribute the GPL-licensed program, they retain the freedom to use the software within their organisation as they see fit.

Furthermore, works, including software programs, created through the use of the GPL-licensed program are not obliged to be governed by the GPL.

Software developer Allison Randal has proposed that the GPLv3 license may be made easier for readers who are not lawyers while retaining its terms and legal efficacy.

An open-source license is recognised as an enforceable contract, according to a ruling made in April 2017 by a federal court in the United States.

In October 2021, the Software Freedom Conservancy (SFC) initiated legal action against Vizio for breach of contract, as an end user sought access to the source code for Vizio’s televisions.

During this ongoing legal dispute, a federal judge has affirmed that the GPL serves as both an enforceable contract for end users and a licensing arrangement for copyright holders.


The text of the GNU GPL is itself protected by copyright, and the FSF is the copyright holder.

The FSF allows for the creation of new licenses that are derived from the GPL, provided that they do not include the GPL preamble without explicit legal permission.

However, this practice is discouraged because it can lead to compatibility issues with the GPL and contribute to what’s perceived as an excessive proliferation of licenses.

The GNU project has also introduced other licenses. These are:

  • GNU Lesser General Public License,
  • GNU Free Documentation License, and
  • Affero General Public License.

It’s worth noting that the text of the GPL is not subject to the GPL itself. The GPL’s copyright explicitly prohibits modifications to the license text.

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Nevertheless, it is legal to duplicate and distribute the license because the GPL requires that software users acquire “a copy of this License along with the Program.”

According to the GPL FAQ, it’s possible for anyone to create a new license by using a modified version of the GPL, as long as they give the new license a different name, avoid referencing “GNU,” and remove the preamble.

However, the preamble can be included in a modified license if additional permission to do so is obtained from the Free Software Foundation.

Text and Other Media

As long as it is apparent what “source code” (expressed as “the preferred form of the work for making alterations to it”) is, the GNU General Public License (GPL) can be used for text documents or various types of media.

However, for manuals and textbooks, the Free Software Foundation (FSF) suggests using the GNU Free Documentation License (GFDL), which was specifically designed for such purposes.

Interestingly, in 2006, Debian developers recommended licensing documentation for their project under the GPL due to the incompatibility between the GFDL and the GPL (text licensed under the GFDL cannot be integrated into GPL software).

Additionally, the FLOSS Manuals Foundation, an organisation dedicated to creating manuals for free software, decided to opt for the GPL over the GFDL for its texts in 2007.

Any documents or images produced using computer fonts may be required to adhere to the GPL’s guidelines when the GPL is applied to those fonts.

However, this isn’t the case in countries that consider typefaces (the visual design of fonts) as utilitarian and not eligible for copyright protection, while font files are treated as copyrighted computer software (which can complicate font embedding since the document could be seen as ‘linked’ to the font).

In other words, embedding a vector font in a document might necessitate releasing the document under the GPL, but a rasterised rendering of the font would not be subject to the GPL.

The FSF does offer an exception in situations where the desired outcome is not accomplished.

Legal Hurdles for Application Stores

The GNU General Public License (GPL) encounters compatibility issues with various application digital distribution systems, including the Mac App Store and certain other software distribution platforms, whether on smartphones or computers.

The primary issue arises from the right “to make a copy for your neighbor,” a right that is infringed upon by digital rights management (DRM) systems integrated into these platforms to prevent the unauthorised copying of paid software.

Even if an application is available for free within a particular application store, it can still run afoul of that store’s terms and conditions.

It’s crucial to differentiate between an app store that offers proprietary DRM-restricted software and the more widespread notion of digital distribution via online software repositories.

Almost all current Unix systems and Linux distributions, such as NetBSD, Ubuntu, Debian, FreeBSD, and Fedora have their own application repositories.

Despite the core project’s prohibition on GPL-licensed code in the base system, repositories still include GPL-licensed software applications, such as in the case of OpenBSD.

In other instances, such as the Ubuntu App Store, both proprietary commercial software applications and GPL-licensed applications coexist within the same platform.

The incompatibility of GPL-licensed apps with platforms like the Mac App Store is not an inherent issue with the idea of an app store itself but is instead specifically linked to Apple’s terms of use, which require all apps in the store to adhere to Apple’s DRM restrictions.

In contrast, Ubuntu’s app store doesn’t impose such a requirement, stating that “These terms do not limit or restrict your rights under any applicable open-source software licenses.”

Landmark Cases of GPL Violations and Legal Enforcement

The initial known instance of GPL violation dates back to 1989 when NeXT expanded the GCC compiler to include Objective-C support but failed to release these changes publicly.

Following an investigation, they eventually provided a public patch, and no lawsuit was initiated for this infringement.

MySQL AB filed a lawsuit against Progress NuSphere in a US district court in 2002. It was filled for claimed trademark and copyright breaches,

The claim was based on NuSphere’s purported use of MySQL’s GPL-licensed code in conjunction with NuSphere Gemini tables without adhering to the GPL’s terms.

The parties started negotiating a settlement following a preliminary court hearing and ultimately, a settlement was reached. The hearing was held before Judge Patti Saris in February 2002.

Following the hearing, the FSF commented that “Judge Saris clearly recognises the GNU GPL as an enforceable and binding license.”

Daniel Wallace filed a lawsuit in the Southern District of Indiana against the FSF in May 2005. According to Daniel Wallace, the GPL amounted to an unlawful attempt to set prices, specifically at zero.

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However, the case was dismissed in March 2006 due to Wallace’s failure to present a valid antitrust claim.

The court emphasised that the GPL actually encourages competition and the distribution of computer operating systems, resulting in direct benefits to consumers.

Wallace was not granted the opportunity to amend his complaint further, and he was directed to cover the legal expenses incurred by the FSF.

In a case involving trade secrets drawn from GPL-licensed work, it was concluded that the GPL was immaterial. The Seoul Central District Court concluded this in September 2005.

The defendants claimed that they were not infringing on trade secret laws by stating that it was difficult to protect trade secrets while adhering to the GPL and disseminating the work. However, this argument was ultimately dismissed.

On September 6, 2006, the project achieved victory in a court battle against D-Link Germany GmbH regarding D-Link’s unauthorised use of parts of the

Linux kernel in their distributed storage devices.

The court’s judgment affirmed the validity and legally binding nature of the GPL, and this precedent was established in a German court.

The Software Freedom Law Center and the BusyBox developers launched a campaign to secure GPL compliance from BusyBox distributors in embedded devices at the end of 2007.

They pursued legal action against those who refused to comply with GPL obligations, marking the first instances in the United States of courts being used to enforce such obligations.

How to Release Your Program Under GNU Licenses: Step-by-Step

Here’s a concise overview of the steps you need to take to release a program under one of the GNU licenses:

  1. Obtain a copyright disclaimer from your employer or school.
  2. Ensure that each file in your program includes the appropriate copyright notices. Which license versions consumers are permitted to use should be made very clear.
  3. Include a COPYING file containing a copy of either the GNU GPL or GNU AGPL.
  4. If you are using the GNU LGPL, please include a COPYING.LESSER file that contains a copy of this license.
  5. Insert a license notice into each source file.
  6. Optionally, you can have the program display a startup notice.
  7. If you’re using the GNU AGPL, make sure the program offers copies of its source code.

To complete this process, it is necessary to include two elements in each source file of your program:

  • a copyright notice, such as “Copyright 2023 Mia,” and
  • a statement granting copying permission.

This statement should indicate that the program is distributed under the terms of the GNU General Public License, Lesser GPL, or Affero GPL.


Understanding and properly applying copyright and licensing terms, especially within the GNU license family, is essential for both developers and users of software.

Ensuring correct copyright files, license specifications, and legal notices are included in a software package is crucial to avoid copyright violations and maintain compliance with license conditions.

Future versions of popular software licenses may continue to evolve to address new challenges.

Ultimately, a clear grasp of licensing terms and adherence to license documentation is essential when dealing with software distribution, whether in object code form or source code form, physical products, or larger programs.


For what purpose was GPL intended?

Richard Stallman authored the GPL in 1989, intending it for utilisation with software released within the GNU Project – Free Software Foundation.

Stallman aimed to create a universal license that could be applied to any project, enabling multiple projects to share code effectively.

Name the most popular software licenses in the free and open-source software domain.

Throughout history, the GPL license family has consistently ranked among the most widely used software licenses in the realm of free and open-source software.

Prominent examples of free software programs governed by the GPL include the Linux kernel and the GNU Compiler Collection (GCC).

How can I ensure correct compliance with GNU copyright and licensing terms?

To ensure correct compliance, carefully read and understand the specific terms of the GNU license associated with the software you intend to use or distribute.

Name different license versions of GPL.

GPLv1, GPLv2, and GPLv3 are 3 different license versions of GPL.

What is one alternative approach to complying with copyleft provisions when distributing software?

Instead of immediately offering the source code alongside the software, an alternative method to meet copyleft requirements is to furnish a written offer to provide the source code on a physical medium, like a CD, upon request.