Proposal to Change DataJoint Python License

[dimitri-yatsenko]

Proposal to Change DataJoint Python License from LGPL v2.1 to MIT or Apache 2.0

Hi DataJoint Python Community and Contributors,

We propose a significant change to the licensing of DataJoint Python. We are considering moving from our current GNU Lesser General Public License v2.1 (LGPL v2.1) to a more permissive open-source license. Specifically, we are evaluating both the MIT License and the Apache License 2.0. This initiative is being led by DataJoint Inc., the company that employs the principal contributor and founder and maintains this main code repository for DataJoint Python, and which also owns the trademark for the name "DataJoint".

Why are we proposing this change?

Our primary goal remains to make DataJoint Python as accessible and easy to adopt as possible for the widest range of scientific and technical projects. The LGPL v2.1 license, while promoting the sharing of improvements to the library itself, can sometimes create complexities for users who wish to integrate DataJoint Python into projects with different licensing requirements, particularly proprietary software or projects under other open-source licenses that may not be compatible with LGPL v2.1.

Moving to a more permissive license like MIT or Apache 2.0 would significantly reduce these licensing hurdles. These licenses generally allow users to freely use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the software with minimal restrictions, making it much easier to incorporate DataJoint Python into diverse workflows and applications without the copyleft obligations of LGPL v2.1 on your own code.

MIT vs. Apache 2.0: Understanding the Differences and Trademark Considerations

While both the MIT and Apache 2.0 licenses are considered permissive and would allow for broader adoption, they have some key differences that are important to consider during this deliberation, especially in light of DataJoint Inc.'s ownership of the "DataJoint" trademark:

• Simplicity: The MIT License is generally shorter and simpler, often preferred for its ease of understanding and implementation.
• Patent Grant: The Apache License 2.0 includes an explicit grant of patent rights from contributors to users. The MIT license does not have a specific patent grant clause, although patent rights might be implicitly granted through the permission to "use" the software. The Apache 2.0 license offers more clarity and protection in this regard.
• Attribution and Notification: Both licenses require including the original copyright and license notice. However, the Apache License 2.0 also requires including a NOTICE file that may contain attribution notices and requires users to state significant modifications they make to the licensed code in their distributions. The MIT license is less prescriptive about detailing changes.
• Trademark: This is where the licenses differ in a way relevant to DataJoint Inc. owning the "DataJoint" trademark:
  • The Apache License 2.0 explicitly does not grant permission to use the trade names, trademarks, service marks, or product names of the licensor, except as required for reasonable and customary use in describing the origin of the Work.
  • The MIT license is silent on trademarks. While trademark law still applies regardless of the code license, the lack of an explicit exclusion in the MIT license means that users need to be mindful of standard trademark principles regarding not implying endorsement or affiliation when using the DataJoint Python software. The Apache 2.0 license provides clearer boundaries regarding the use of the "DataJoint" name.

Both licenses would achieve our goal of easing adoption compared to LGPL v2.1, but they offer slightly different terms regarding patents, attribution, and how the project's trademark is addressed within the license text itself.

What does this mean for you and the process?

Changing the license of an established open-source project like DataJoint Python requires careful consideration and, importantly, the consent of our valued contributors. While DataJoint Inc. controls the main repository and the main contributor is part of the company, under copyright law, the original copyright holders of code contributed under the LGPL v2.1 license who are not employees of DataJoint Inc. need to agree to have their contributions re-licensed under the new, more permissive license (either MIT or Apache 2.0, depending on the final decision).

Therefore, DataJoint Inc. is opening this discussion to gather your input and feedback on this proposed change and which of the two permissive licenses (MIT or Apache 2.0) you believe would be the best fit for DataJoint Python and its community moving forward. We want to hear your thoughts, concerns, or any potential issues you foresee with this transition and with either of these licenses, particularly considering the points about patent grants and trademark handling.

Our Plan for Facilitating the Transition and Making the Decision:

1. Community Discussion (Starting Now): This post kicks off a period of open discussion. Please share your thoughts on the proposed move away from LGPL v2.1 and your preference between the MIT and Apache 2.0 licenses in the comments below. Explain your reasoning!
2. Reaching out to Contributors: DataJoint Inc. will be actively reaching out to individuals who have made significant code contributions to DataJoint Python while not being employees of DataJoint Inc. at the time of contribution. We will inform them of this proposal and formally request their consent to re-license their contributions under both the MIT and Apache 2.0 licenses. This will give us the necessary permissions to choose the preferred license based on community feedback and overall contributor consent. We will keep a clear record of all consents received.
3. Addressing Concerns and Deliberation: We will actively monitor this discussion and other channels to address any questions or concerns raised by the community and contributors. The DataJoint Inc. team will deliberate based on community feedback, the level of contributor consent obtained, and the specifics of each license (including the trademark aspects) to make a final decision between MIT and Apache 2.0.
4. Planned Transition Date: If we receive sufficient consent from non-company contributors and reach a decision between MIT and Apache 2.0 without significant, unresolvable objections from the community, we plan to make the official license change on October 1, 2025. This provides a clear timeline for this process and the deliberation period.
5. Technical Steps: On the planned transition date, we will update the LICENSE file in the GitHub repository with the chosen license (either MIT or Apache 2.0), update the README and documentation to reflect the new license, and ensure package metadata is updated. We may also publish a separate, clear trademark policy for DataJoint to provide additional guidance to users.

We need your input!

Your feedback is incredibly valuable as we consider this change and make a decision between the MIT and Apache 2.0 licenses. Please use this discussion thread to share your thoughts and preferences. If you are a contributor who was not an employee of DataJoint Inc. at the time of your contributions, please also be on the lookout for direct communication from us regarding your consent.

We believe that moving to either the MIT or Apache 2.0 license will be a significant positive step for the DataJoint Python community, fostering wider adoption and innovation while providing clarity on licensing and trademark usage.

Thank you for your time and contributions to DataJoint Python.

Sincerely,

The DataJoint Inc. Team

[dimitri-yatsenko]

I have made some changes to include considerations for trademarks, the role of DataJoint Inc., and the choice between MIT and Apache 2.0.

[dimitri-yatsenko]

Tagging principal co-developers: @eywalker @fabiansinz