The Risks of Dual Licensing in The Pioneering Landscape of Contemporary Open Source

Enrico Schaefer - September 28, 2023 - Open Source Software


Open-source software development isn’t a new kid on the block, but its importance has skyrocketed with the emergence of game-changing technologies like blockchain and AI. As more and more projects in these fields adopt open-source licensing, the legal complexities tied to these licenses are becoming increasingly relevant, with dual licensing being a case in point.

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Choosing the Right Open Source License For Your Project

Choosing the suitable licensing model at the inception of an open-source project is not just a legal formality; it’s a strategic imperative. Unlike traditional proprietary software, SaaS or PaaS business models where license terms can often be renegotiated or amended in subsequent contract cycles, open-source licensing is far less forgiving of afterthoughts. Once code has been released under a particular open-source license, changing that license can be a Herculean task fraught with legal complexities and community backlash.

The challenges are significant. First, you may need to secure permissions from every contributor to the project, a logistical issue for larger, more collaborative initiatives. Second, altering the license could alienate a project’s community, leading to forks or abandonment. Third, a change in licensing can have downstream effects on derivative works and integrations, potentially leading to legal disputes or claims of copyright or patent infringement. Therefore, every open source project must evaluate its license choices and consult legal experts before making your code publicly available.

Overview of Open Source License Types

While the intricacies of open-source licenses can be complex, they generally fall into two broad categories: permissive licenses like the MIT License and copyleft licenses like the GNU General Public License (GPL). Permissive licenses offer more freedom for reuse and are generally business-friendly, while copyleft licenses require any derivative work to be open-sourced under the same license.

Given the complexities and high stakes involved, consulting with legal experts specializing in open-source licensing is imperative. Our team of open-source attorneys is well-equipped to guide you through the landscape of open-source licenses, identify legal risks, and ensure you make an informed decision that aligns with your legal obligations and strategic objectives.

The Best of Both Worlds: Understanding Dual Licensing in Open Source

Dual licensing is a clever workaround for a classic problem in the open-source world. It’s designed for businesses that are usually cautious about incorporating open-source elements into their proprietary work. The reason for this caution is often the “copyleft” requirements in licenses like the GPL, which could force companies to make their code public if mixed with open-source code, putting their intellectual property at risk.

But here’s where dual licensing comes in handy. It lets businesses use and adapt an open-source project—typically under a stringent license like the AGPL—without disclosing their tweaks to the world. This protects the business interests and resonates with what the open-source community has advocated: more corporate participation. More corporate resources can mean faster development and broader adoption of open-source projects.

How do you have an honest conversation with someone where you say “yes, I will need the work you did for free, to be assigned over to me, so that I can make money on it”?

RoBlaBlog – Thoughts on dual licensing and contrib agreements (Posted on 2010-02-27 by robla)

While dual licensing has its detractors, there’s no denying its effectiveness in reconciling the differing needs of various parties involved. By allowing businesses to contribute to open-source initiatives without giving up their proprietary edge, dual licensing creates a win-win scenario for everyone in the ecosystem.

Navigating the Legal Minefield of Dual Licensing

Dual licensing, while offering a flexible framework for both open-source communities and commercial entities, is not without its legal pitfalls. One of the most pressing concerns is the potential for license incompatibility. For instance, if a project is dual-licensed under a permissive license like MIT and a copyleft license like GPL, contributors, and users must be acutely aware of the obligations and restrictions each license imposes. Failing to comply with the terms of either license could result in legal repercussions, including copyright infringement claims.

Another significant legal issue is the matter of contributor agreements. In a dual-licensed project, contributors must often sign a Contributor License Agreement (CLA) (see examples below) that explicitly outlines the terms under which their contributions can be used. Usually, this is an irrevocable license or assignment of copyright and patent rights to the project managers. This is particularly important for projects that may later change one of the dual licenses or add a commercial one. Without a comprehensive CLA, the project could face legal challenges from contributors who disagree with the license change, leading to project forks, litigation, or even the dissolution of the project.

The Importance of Contributor License Agreements in Dual Licensing

Contributor License Agreements (CLAs) are still controversial but are becoming more accepted and standard. CLAs are the legal backbone of any dual-licensed open-source project. These agreements define the terms under which contributions are made to the project, safeguarding against future legal complications. Key terms that should be included in a CLA often encompass the scope of the license granted to the project, address moral rights, select a license or assignment approach to contributions, address any warranties or disclaimers, and provide a path for dispute resolution.

One critical term is the explicit acknowledgment that the contributor permits the project to re-license their contributions under different licenses in the future. This is particularly vital for dual-licensed projects that may need to adapt their licensing strategy to accommodate evolving legal or commercial landscapes. Without such a provision, the project could face legal hurdles if it decides to change one of its licenses.

Failure to have a robust CLA can lead to various legal issues, ranging from intellectual property disputes to potential litigation. In the worst-case scenario, disagreements over licensing could result in Open Source project forks or even the dissolution of the project, thereby undermining the collaborative spirit that is the psychological and emotional premise of some open-source communities.

Sample CLAs – Forms, Formats and Examples

Before we delve into sample Contributor License Agreements (CLAs), it’s crucial to underscore that the templates and forms below are intended solely for educational purposes. They are designed to give you a foundational understanding of the critical terms and conditions commonly found in CLAs, thereby enabling more informed discussions with your open source attorneys. Before adopting any CLA template or example for your project, consulting with an attorney specializing in open-source licensing is imperative.

Open-source licensing is a complex legal field with nuances that can significantly impact the future of your project’s future. A one-size-fits-all approach rarely suffices; minor oversights can lead to substantial legal complications. Here are some sample CLAs.

  • The Next Generation of Contributor Agreements website. Fiduciary License Agreement (FLA) with provisions recommended by the Free Software Foundation Europe (FSFE) or build your own custom Contributor License Agreement by choosing your own options.  Read more
  • GitHub repository of sample Contributor License Agreement (CLA). Once you have your CLA, this CLA assistant says it will streamline your workflow and let the CLA assistant handle the legal side of contributions to a repository for you. CLA assistant enables contributors to sign CLAs from within a pull request. Read more
  • Google’s Contributor License Agreement: Google provides a CLA that covers contributions to all Google open-source projects. It allows the contributor to retain ownership while granting Google the legal rights to use the contribution. Read more
  • LinkedIn Article on Dual-Licensing and CLAs: This article discusses managing copyright and contribution agreements for dual-licensed software projects. It also touches on the importance of establishing a Contributor License Agreement. Read more
  • GitHub repository of sample commercial license templates (Not CLAs) for open source projects that want to use the sustainable dual-license model. Read more


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This page has been written, edited, and reviewed by a team of legal writers following our comprehensive editorial guidelines. This page was approved by attorney Enrico Schaefer, who has more than 20 years of legal experience as a practicing Business, IP, and Technology Law litigation attorney.