Why Open Source Forking Is a Hot-Button Issue

Introduction

In recent times, open source forking has become a contentious topic. As more companies engage with open source, it’s becoming increasingly evident that open source isn’t simply a business model. Companies like HashiCorp and Redis Labs have found themselves in the spotlight due to forking initiated by community-led projects like OpenTofu and Valkey. This article explores the reasons behind these forking initiatives and the broader implications for the open source ecosystem.

What Is Forking?

Forking in open source refers to copying an existing codebase and creating a separate, independent version of the project. It is essentially the process of taking an open source project in a different direction—often with new governance, community, and objectives. Unlike proprietary software, which restricts modifications and redistribution, open source forking is a standard practice allowed by the software’s license. Typically, the new project will also have a different name, as trademarks do not transfer with the code.

Recent Notable Forks

Recent years have seen prominent forks of key open source projects. Examples include:

• OpenTofu and Valkey: These projects emerged as forks of HashiCorp and Redis Labs after the original projects moved from open source to proprietary licenses.
• AWS OpenSearch: Amazon Web Services forked ElasticSearch to create OpenSearch when Elastic shifted licensing terms.

Forking is considered the “ultimate weapon” for community control in open source. It’s a safeguard that ensures projects remain truly open, even if the original maintainer changes direction.

Why Companies Fork

The reason for forking usually revolves around a conflict in governance, licensing, or project direction. The community or stakeholders may feel the project no longer serves the interests of the community or adheres to the values of open source. When HashiCorp moved from an open source to a proprietary license, OpenTofu was created to keep the original spirit of HashiCorp’s software alive.

Similarly, when Elastic decided to change its licensing terms, AWS created OpenSearch as an alternative that could continue to grow in a truly open environment. These forks are intended to preserve user freedom and project accessibility.

Risks and Challenges of Forking

Forking a project is not without challenges. Here are a few considerations:

1. Community Fragmentation: When a fork is created, it often divides the existing community between the original project and the new version. This split can dilute developer resources, slowing innovation.
2. Brand Recognition and Confusion: The new fork must differentiate itself and build an identity distinct from the original. Brand recognition and user trust can take years to develop, meaning that gaining traction might be challenging for the fork.
3. Resource Investment: Creating a fork requires a significant investment of resources, both in development and marketing, to ensure that it is seen as a viable alternative.

The Ethics of Forking

Forking raises questions about the ethics of open source development. Some argue that commercial entities exploiting community contributions while maintaining control over the project’s direction betrays the principles of open source. Forks, therefore, act as an essential community mechanism to counteract what can be seen as corporate overreach.

Forks like OpenTofu and OpenSearch aim to maintain community ownership of the codebase, encouraging others to contribute without the fear that their work will eventually be locked behind a proprietary wall. They underscore that forking is often less about competition and more about preserving the core ideals of open collaboration.

Forking has always been and will likely continue to be a core tenet of the open source world. It embodies the values of freedom and collaboration. As open source grows in popularity, companies must recognize that community trust is a valuable asset. If they choose to go proprietary, there will always be community-driven efforts to fork and maintain the project’s original ethos.

Ultimately, forking is not just a technical process—it’s a profound statement about control, governance, and the future of open software development.

What Is Open Source Software?

To qualify as open source, a codebase must adhere to the Open Source Definition (OSD) maintained by the Open Source Initiative (OSI). This definition contains ten key criteria, with requirements 5 and 6 being especially significant, as they ensure the code can be freely used by anyone for any purpose without limitations. This unrestricted access drives open source software’s massive adoption—by 2023, an estimated 96% of all software included open source dependencies, highlighting its widespread importance in software development today.

The freedom that open source offers ensures that device manufacturers and developers can confidently distribute software, provided they meet the license conditions. These typically include giving appropriate credit to the original developers and making the source code publicly available. As long as they adhere to these requirements, there is no need for additional permissions, licenses, or royalties, instilling confidence in using and redistributing the software.

However, not all open-source-like licenses meet these criteria. When a software license doesn’t comply with the OSD, it’s often due to added ethical or commercial restrictions that control how or by whom the software can be used. Such changes usually serve the interest of enhancing the commercial sponsor’s revenue, moving the software away from genuine open source ideals toward proprietary models.

“Public Source” and Open Washing

Licenses that don’t align with the OSD often create confusion. Technically, these licenses are proprietary, but since the source code is still publicly accessible, many misunderstand them as open source. Sometimes referred to as “public source,” “distributed source,” or even branded as “fair source,” these models aren’t truly open source, primarily because they don’t allow free-flowing, unrestricted usage.

A related issue is “open washing,” where a distributor misleadingly suggests that their code is genuinely open source by implying compliance with open source principles. This misrepresentation occurs when software is promoted as open source while retaining commercial or restrictive elements that fundamentally violate open source norms.

Shifting the Future, Not the Past

One of the key attributes of open source is that once a project has been distributed under an open source license, it remains open under those terms indefinitely for that particular version. Future versions might adopt proprietary or restricted licenses, but earlier versions always remain freely available under their original open source licenses.

This is where forking becomes crucial in safeguarding the interests of the open source community. When a project shifts its licensing model, the community can fork the last openly available version, ensuring it continues to be developed and freely accessible under its original license. This is exactly what happened when HashiCorp transitioned to a proprietary license; the open source community responded by creating the OpenTofu fork, ensuring that the spirit and availability of the software continued.

This principle of “shifting the future, not the past” ensures that the contributions of the community and developers are not retroactively constrained by new restrictions. Even when a commercial entity moves towards a more controlled, proprietary approach, the open source community maintains the right to the original, unrestricted code.

A Historic Weapon of Community Control

Within open source communities, forking has always been seen as the “ultimate weapon” to maintain control over a project. Forking allows community members to create a new version of an open source project if its leadership becomes disconnected from the community’s needs or makes unpopular decisions. This dynamic has been evident in past community forks like Sun and Matrix. It’s a vital tool that ensures the community can push back and continue developing software that aligns with its vision.

Commercial Sponsors and the Changing Landscape of Forking

In recent years, commercial entities have increasingly shifted away from open source licensing, creating a new era of forking. These moves—like those by Redis Labs, MongoDB, ElasticSearch, and HashiCorp—have normalized, leading to less community backlash over time. Companies that use an “open core” business model may start with an open source foundation to attract users but then restrict access by moving toward proprietary licenses.

Assessing the health of a project’s community can be key to predicting its stability. Projects with limited contributors outside of a company’s employees are more likely to experience licensing shifts. A vibrant and diverse community acts as a protective layer against this transition by potentially forking the project when necessary.

The Role of Forking in Maintaining Open Source

Forking has become a crucial community response to companies shifting licenses to more restrictive models. Notable examples include AWS’s OpenSearch fork after Elastic changed the license for ElasticSearch. AWS’s fork aimed to maintain the open source project’s continuity and usability despite Elastic’s restrictive licensing.

Forking by major users like AWS introduces an interesting power dynamic. AWS used Elastic’s open source code under its license terms, ultimately creating a separate project (OpenSearch) after Elastic introduced proprietary elements. This is a direct demonstration of how forks serve as a community control mechanism, even when the “community” is a major corporate entity.

The open source software ethos is rooted in freedom and collaboration. Forking plays an important role in preserving that ethos, enabling community members to act when commercial interests try to alter the foundational agreements. These recent changes to licensing models and the increased use of forks signal a shifting power dynamic—where both community and corporate interests converge in the evolving landscape of open source.

Successful Forks

Forking in the open source community is a measure of success that is not about financial gain but rather about code quality, contribution, and adoption. A good example of this dynamic is the fork of MariaDB from MySQL. While MySQL has more GitHub stars than MariaDB, MariaDB boasts more community contributors—demonstrating the strength of its developer base.

The financial success of a forked version is often highlighted by commercial entities, particularly those that may have switched to a proprietary model post-fork. Redis and MongoDB, for example, continue to thrive commercially despite moving away from their original open source licenses. MongoDB even admitted that open source initially served as a “marketing tool”—a strategy often termed “bait and switch,” where an open source option later transitions to a proprietary license.

Challenges and New Successes in Forking

Historically, forking has faced obstacles such as the cost and complexity involved, which has made successful forks relatively rare. However, the Linux Foundation’s Valkey fork may indicate a change in the dynamics of forking. Recent research from Percona shows that 70% of Redis Labs users have sought alternatives after their license shift, with a significant percentage testing or adopting the Valkey fork. This trend suggests a renewed vigor in the community to push back against restrictive licensing changes.

Stephen O’Grady from Redmonk pointed out how quickly the Valkey fork was executed—with major players like AWS and Google getting involved—signaling a potential shift in how easily forks can now be created and supported.

The Future of Open Source and Forking

Companies like Redis often claim that moves away from open source licensing are necessary to prevent “strip mining” of their code by cloud giants. While cloud companies like AWS may use open source code commercially, this is in line with open source principles—that anyone can use the code freely. The original choice to make code open source lies with the companies themselves, and the subsequent shift in licensing remains an ethical gray area, particularly for the community.

Despite normalization of these shifts, they continue to be seen as a breach of trust within the open source community. From the perspective of smaller open source companies like Redis, forks like Valkey may seem like retaliation from much larger entities. This backlash appears to be the community’s response to becoming weary of “bait and switch” tactics.

Conclusion

Open source is fundamentally about community control, transparency, and collaboration. The community’s ability to fork is an effective way to counter “bait and switch” approaches, and today, some of the community’s biggest supporters are major tech players like AWS. This could signal a change for companies considering an open source model without the long-term commitment required to support a true open source community. The recent events serve as a reminder that open source is not just a marketing gimmick; it’s a lifelong commitment to openness and collaboration.