Open Source Software Licensing

Software licensing is a critical yet often overlooked aspect of software development. As a developer, the license you choose for your project can have far-reaching implications on how your software is used, modified, and distributed. This decision becomes even more complex in the realm of open source software.

Open source licenses make the source code available for use, modification, and distribution based on agreed-upon terms and conditions. But even within the open source world, licenses can vary widely. Do you want a permissive license like MIT or BSD, which allows for maximum freedom of use? Or a copyleft license like GPL, which ensures derivative works remain open source? Perhaps you're considering a creative commons or public domain license?

While choosing the initial license for your project is crucial, an equally important consideration is what happens if you need to change your license later on. This seemingly simple decision can have profound impacts on your project and community.

In this article, we'll explore the landscape of open source licensing, with a particular focus on the challenges and considerations surrounding license changes. We'll address questions such as:

1. What are the different types of open source licenses and their implications?

2. How do you choose the right license for your project?

3. What motivates projects to change their licenses?

4. What are the potential consequences of changing an open source license?

5. How can you navigate a license change while respecting your community?

By understanding these issues, you'll be better equipped to make informed decisions about licensing throughout your project's lifecycle, from its initial release to potential future changes.

What are the different types of licenses available to developers?

• CopyLeft: Copyleft licenses like GPL, AGPL, and LGPL are often described as "viral" because they require derivative works to be distributed under similar terms. The GPL mandates source sharing for all derivatives, AGPL extends this requirement to network-accessed derivatives, while LGPL relaxes the requirement for works that merely link to the original software.

• Permissive open source licenses like MIT, BSD, and Apache offer less restrictive terms than copyleft licenses, while still maintaining attribution requirements and liability protections. These licenses differ mainly in their handling of patent claims and trademark use, so careful consideration is needed when choosing between them.

• Creative Commons licenses offer a modular approach to licensing, with options for attribution (BY), share-alike (SA), non-commercial use (NC), and no derivatives (ND). However, including NC or ND modules makes the license incompatible with the OSI definition of open source, potentially causing compatibility issues with other open source projects.

• While releasing software into the Public Domain may seem appealing for maximum freedom, it lacks crucial protections like warranty waivers. For those wanting minimal restrictions, alternatives like the Unlicense offer similar freedoms while still protecting the creator from liability.

How do you choose the right license for your project?

Understanding and choosing the right license for your open source project is crucial for both legal and practical reasons. The right license provides legal protection, defining how your software can be used, modified, and distributed while potentially shielding you from liability. It also significantly impacts your project's adoption and community building. 

Some licenses are more attractive to businesses, while others appeal more to individual developers or academic institutions. Your choice can encourage or deter potential contributors, affecting the growth and collaboration around your project.

Moreover, your license choice has far-reaching implications for your project's future. It determines compatibility with other software, potentially enabling or preventing integration with useful tools or libraries. If you plan to monetize your project, certain licenses are more conducive to commercial use than others. 

The license you choose now can also affect your ability to change direction in the future, as some licenses make it difficult to switch later on. Finally, your license reflects your values about software freedom and knowledge sharing, and ensures compliance with the terms of any third-party code you're using. By carefully considering these factors, you can choose a license that aligns with your project goals, protects your interests, and sets the stage for your project's growth and success.

What motivates projects to change their licenses?

Open source projects often consider changing their licenses for various reasons, but these motivations often fall into three main categories: legal and compatibility concerns, evolving project needs, and strategic business considerations. As we will see in the case studies below.

Legal and compatibility issues are often at the forefront of license change decisions. As the open source ecosystem grows and evolves, projects may find that their current licenses are causing integration problems or legal ambiguities. For instance, a project might move from a custom or outdated license to a more widely recognized one, such as Apache 2.0 or MIT. This change can simplify legal review processes, increase trust in the project, and facilitate easier integration with other open source tools. Additionally, as legal landscapes shift, especially around issues like patent rights, projects may need to update their licenses to provide better protection for both contributors and users.

The evolving needs of a growing project can also necessitate license changes. What works for a small hobby project may not be suitable for a large, widely-used tool with a diverse contributor base. As projects mature, they often need to reconsider their licensing to better manage contributions, ensure long-term sustainability, and align with the project's expanding goals. 

This might involve moving from a very permissive license to one that ensures contributions remain open source, or vice versa, depending on the project's direction. Furthermore, as technology landscapes change, introducing new concepts like cloud computing or AI applications, licenses may need to be updated to cover these new use cases adequately.

Strategic business considerations play an increasingly important role in open source licensing decisions, especially as more companies build business models around open source software. A project might change its license to better support its monetization strategy, balancing the need for openness with the desire to protect against unfair commercial exploitation. 

For example, a project might move from a very permissive license to a copyleft one to ensure that improvements made by large companies are shared back with the community. Conversely, a project might adopt a more permissive license to encourage wider adoption, especially among corporate users. The influence of funding organizations or changes in project ownership can also drive license changes, as new stakeholders may have different priorities or philosophical approaches to open source.

These motivations often intersect and overlap, reflecting the complex decision-making process involved in open source licensing. As we'll see in the following case studies, real-world projects often grapple with multiple factors when considering a license change, highlighting the importance of carefully considering both current needs and potential future scenarios when making licensing decisions.

What are the potential consequences of changing an open source license?

Changing an open source license can lead to several outcomes:

1. Community and ecosystem impact

2. Legal and logistical challenges

3. Project adoption and business implications

Community and ecosystem impact:

License changes can split user groups. The TechStart case shows how moving from MIT to GPL could alienate users integrating the software into proprietary projects. This might create separate user bases, with some sticking to the old license version. New license terms can attract different contributors and discourage others. In extreme cases, dissatisfied members might create a separate version under the original license, dividing both users and developers.

The OpenSSL example demonstrates how license changes can increase community involvement, but risk losing those who disagree with new terms. Changes in major projects can affect others in the open source space. Dependent projects may need to reassess their own licenses, potentially causing a ripple effect across multiple projects.

Legal and logistical challenges:

For established projects, changing licenses involves significant work, as seen in the OpenSSL case. They had to reach out to over 400 contributors across two decades, some untraceable or deceased. This process can consume resources that could otherwise go into development. Improperly executed changes risk legal issues. Users might face unexpected legal problems if unaware of or misunderstanding the new license implications. 

New licenses may introduce barriers to contribution, such as requiring new agreements, further complicating the project's legal landscape. The OpenSSL case highlights the benefits of having contributor agreements from the start for large projects, easing future changes. It also shows the value of transparency, as seen in their public tracking of contributor agreements.

Project adoption and business implications:

License choice significantly impacts project adoption and commercial viability. The OpenSSL case shows that adopting a more compatible, recognized license like Apache 2.0 can boost adoption and integration with other projects. It can clarify legal matters, particularly regarding patents, appealing to both individual and corporate users. Conversely, as TechStart considered, stricter licenses could reduce adoption, especially among commercial users. This might affect project growth and long-term sustainability. 

Yet, it could prevent large companies from benefiting without contributing back, addressing one of TechStart's concerns with their permissive MIT license. License changes can impact business models. TechStart struggled to monetize under the MIT license, facing competition in support services and missing out on improvements by large companies using their software. A license change could address these issues but might introduce new commercial challenges.This is partly covered in the first case study below.

Changing an open source license is a significant decision with wide-ranging effects. It requires careful consideration of project goals, community dynamics, legal implications, and commercial strategies. Effective communication and community involvement in decision-making are crucial for a successful license transition.

Further things to consider:

• Forking risk: Unhappy community members might create a separate version of the project under the old license.

• Trust and reputation effects: How the license change is handled can impact the project's standing in the open source community.

• Contribution barriers: New licenses might introduce additional requirements for contributors, potentially slowing down development.

• Resource allocation: The process of changing licenses can divert time and effort from actual software development.

• Ecosystem dependencies: Projects relying on the software might need to reevaluate their own licensing or usage.

• Patent rights: Some license changes can alter the landscape of patent rights associated with the project.

• Attribution requirements: Different licenses have varying rules about how users must credit the original project.

How can you navigate a license change while respecting your community?

Here are three main points for managing a license change while respecting your community, followed by explanations:

• Open Communication

• Community Engagement

• Smooth Transition Process

Open Communication:

Clear and timely communication is key when changing licenses. Inform your community about the potential change early, explaining the reasons behind the decision in clear, non-technical language. This openness builds trust and allows community members to prepare for the change. For example, if TechStart had decided to change their license, they could have announced their intentions and rationale months in advance, giving users time to assess the impact on their projects. Making more than just an effort to include all contributors/stakeholders is necessary as we will see in the second case study below.

Community Engagement:

Actively involve your community in the decision-making process. Create forums for discussion, listen to feedback, and address concerns. This engagement can reveal unforeseen issues and help refine the approach. In the OpenSSL case, their public tracking of contributor agreements demonstrated good engagement. Going further, they could have held open meetings or surveys to gather input on the new license choice.

Smooth Transition Process:

Plan a gradual, well-documented transition. Provide a timeline for the change, offer guidance on complying with new terms, and update all project documentation. Consider options like dual licensing or grandfathering existing uses to ease the transition. For instance, if TechStart had proceeded with a license change, they could have offered a grace period where both the old and new licenses were valid, allowing users time to adapt. They could also have provided clear steps for users to update their projects to comply with the new license.

By focusing on these three areas, project maintainers can help ensure a respectful and effective license change process that maintains community trust and project momentum.

Two short case studies.

As we've explored the complexities of open source licensing, from choosing the right license to navigating changes, it's clear that these decisions have far-reaching implications. To better understand how these concepts play out in practice, let's examine two revealing case studies. These real-world examples illustrate the challenges and considerations we've discussed, bringing to life the abstract concepts of license selection, project evolution, and community management. 

The first case study focuses on TechStart, a small startup that faced unexpected challenges with its permissive MIT license. The second examines OpenSSL's journey to change its license, highlighting the complexities involved in such a transition for an established project. Through these stories, we'll see firsthand the impact of licensing decisions on project growth, community dynamics, and business strategies, reinforcing the critical importance of thoughtful license consideration throughout a project's lifecycle.

Case Study 1: TechStart and a regret for choosing the wrong license

TechStart, a small software startup, developed an innovative data visualization library called DataViz. Initially, they released DataViz under the MIT License, a permissive open source license, to encourage widespread adoption and community contributions.

The strategy worked well initially. DataViz gained popularity among developers and was integrated into numerous projects, including some commercial applications. TechStart benefited from community contributions that improved and expanded the library's capabilities.

However, as DataViz grew more popular, TechStart faced unexpected challenges:

1. A large tech company, BigTech Inc., incorporated DataViz into their proprietary product without contributing their improvements back to the project.

2. Several companies offered commercial support for DataViz, competing directly with TechStart's own support services.

3. TechStart found it difficult to monetize their work effectively, as the permissive license allowed others to use and redistribute the software freely.

TechStart considered switching to a copyleft license like the GNU General Public License (GPL) to require users to share modifications. However, they realized this change would:

- Potentially alienate existing users, especially those using DataViz in proprietary software.

- Require permission from all past contributors to relicense their contributions.

- Risk fragmentation of the project if some users continued using the MIT-licensed version.

In retrospect, TechStart realized that a more careful consideration of their long-term goals and business model at the outset could have led them to choose a license that better balanced openness with their need to sustain the project financially.

Case Study 2: OpenSSL Move to Change It’s License

OpenSSL, a widely used cryptographic software library, decided to change its license in 2017. This decision and its implementation process highlight several important aspects of open source licensing:

Background:

- OpenSSL was originally licensed under a dual license: the OpenSSL License and the SSLeay License.

- These licenses were unique to the project and not OSI-approved, causing compatibility issues with other open source projects.

In 2017, the OpenSSL project announced plans to relicense under the Apache License 2.0.

The motivation was to improve licensing compatibility with other more modern licensing agreements. They moved to adopt a widely accepted OSI-approved license model. This also helped to clarify terms around patent rights for users of the software.

Challenges Faced:

1. Contributor Agreement: The project needed permission from all copyright holders to change the license.

2. Scale of the Task: OpenSSL had contributions from over 400 individuals over two decades.

3. Tracking Contributors: Some contributors were difficult to locate or had passed away.

4. Corporate Contributions: Some contributions were made by employees of companies, requiring corporate approval.

Implementation Process:

• The OpenSSL team embarked on a massive effort to contact all past contributors.

• They created a public database to track the status of each contributor's agreement.

• The process took several years to complete.

By 2018 OpenSSK 3.0 was released under the Apache License 2.0. This improved compatibility with many other open source projects, and this increased transparency and community engagement. There were many disagreements along the way too, but eventually the change was made.

Key takeaways:

1. The importance of choosing a widely recognized license from the start.

2. The value of having a contributor agreement in place for large projects.

3. The significant effort required to change licenses for long-standing projects.

4. The potential benefits of license change in terms of project compatibility and sustainability.

This case study demonstrates the complexities involved in changing licenses for established open source projects and the importance of careful license consideration from a project's inception.

Sometimes, organizations funding open source projects might push for license changes that align with their interests. While not evident in these case studies, this is a reality for many open source projects, especially those with corporate backing.

These additional motivations highlight the complex interplay of factors that can influence licensing decisions in open source projects. They underscore the importance of carefully considering not just current needs, but also potential future scenarios when choosing or changing a project's license.

What have we learned in Navigating the Complex Landscape of Open Source Licensing

Open source licensing, as we've seen, is a critical aspect of software development that requires careful consideration. The diversity of licenses available offers flexibility but also demands thoughtful selection. Our exploration of different license types, selection criteria, and the motivations and consequences of license changes highlights the complex decisions facing developers and project maintainers.

The case studies of TechStart and OpenSSL underscore a crucial lesson: licensing decisions have far-reaching impacts on a project's adoption, community engagement, and long-term sustainability. They also demonstrate that as projects evolve, so too might their licensing needs.

Ultimately, successful open source licensing is about striking a balance between openness and protection, community interests and project sustainability. As the open source ecosystem continues to evolve, staying informed about licensing trends and being prepared to adapt strategies will be key to navigating this complex landscape effectively.