The GNU General Public License version 3 (GPLv3) stands as a cornerstone in the world of open-source software, providing a comprehensive framework for the distribution and modification of software while ensuring users’ freedom. Created by the Free Software Foundation (FSF), this open-source license builds upon its predecessor, GPLv2, addressing emerging challenges and adapting to the evolving landscape of software development. In this article, we go through into the intricacies of GPLv3, examining its key provisions and the principles that underpin this influential open-source license. 

Key Principles 

At its core, GPLv3 is rooted in the philosophy of free software, as defined by the FSF. The license upholds four essential freedoms for users: the freedom to run the program for any purpose, the freedom to study how the program works and adapt it to one’s needs, the freedom to redistribute copies, and the freedom to improve and share modifications. These principles aim to keep the software free, in the sense that it can be distributed and modified without needing any additional permission from the licensor. Another important principle is that the software must be free of patents that restrict it. In case a patent applies to the software, it must be licensed in parallel with the code. These freedoms, which apply directly to the software, significantly influence the responsibilities and obligations that fall upon the organizations utilizing the software. 

Copyleft Mechanism 

One of the distinctive features of GPLv3 is its copyleft mechanism, a legal concept designed to ensure that derivative works based on GPL-licensed software remain open source. When a developer creates a modified version of a GPLv3-licensed program and distributes it, they are obligated to license the derivative work under GPLv3 as well. This reciprocal nature of the license is intended to preserve the freedoms granted by the GPL and prevent the software from being incorporated into proprietary projects, which represents a critical limitation for organizations. 

Tivoization

To address a concern not explicitly covered in GPLv2, GPLv3 includes provisions against “tivoization.” Tivoization refers to the practice of using technological measures to prevent modified versions of software from running on a particular device. GPLv3 prohibits this by requiring that the recipient of the software has the freedom to install modified versions on their device. This provision ensures that the spirit of the GPL extends beyond the mere availability of source code, but also presents a difficult challenge for companies developing, for example, automotive software. 

Additional Permissions and Conditions 

While GPLv3 retains the core principles of copyleft, it introduces flexibility through the inclusion of additional permissions and conditions. These allow licensors to grant certain freedoms beyond what is mandated by the GPL. For example, the license permits the addition of extra permissions that allow linking the software with other non-free programs. However, these additional permissions must be clearly stated to avoid ambiguity. An interesting aspect is that, while this license allows the creation of derivative works based on the code, it does not allow the creation of new licenses based on GPLv3 terms. 

Compatibility

GPLv3 is designed to be compatible with various other open-source licenses, promoting interoperability within the open-source ecosystem. This compatibility allows developers to combine code from projects with different licenses, fostering collaboration and innovation. However, compatibility is not absolute, and licensors must carefully evaluate the specific terms of each license to ensure compliance. 

Enforcement and Termination

GPLv3 includes provisions for enforcing compliance with its terms. If someone violates the terms of the license, for example, distributes the licensed software under a proprietary license, they may lose their rights to distribute the software and all license’s terms are voided, thus put back in action the protections of the traditional copyright law. As an example of license’s terms enforcement by a court of justice, in 2021 a Venetian court ordered the software developer Nerds Farm s.r.l. that abstains to distribute the plugin E-addons for Elementors, due to the fact that there is merit on the argumentation by developer Ovation s.r.l. (developers of DCE app from where derives E-addons) that the plugin violates the GNU license by not providing appropriate copyright notices and information about modifications. 

Conclusion

The GNU General Public License version 3 is a robust and flexible open-source license that reflects the Free Software Foundation’s commitment to preserving user freedom and fostering collaboration. By incorporating copyleft mechanisms, addressing emerging issues, and introducing additional permissions, GPLv3 continues to be a key player in shaping the open-source landscape. As software development evolves, the principles embedded in GPLv3 serve as a guiding light, ensuring that the ideals of free software persist in the ever-changing digital realm. Given this context, it is critically important for organizations to thoroughly evaluate and confirm that the conditions of GPLv3 align with their specific operational needs and use cases, to uphold the integrity of the open-source ecosystem and ensure legal compliance.