11  Licenses

Important
  • If no license file is provided with the software, the software is considered proprietary and cannot be used by others without written permission.
  • For questions about data and software licenses, please consult your Faculty Data Steward.

11.1 TU Delft licensing policy

TU Delft by default holds the rights to the software created by its employees. In order to apply a pre-approved open source license, you have to follow the guidelines in TU Delft Guidelines on Research Software: Licensing, Registration and Commercialisation. It states:

It is important to remember that in principle TU Delft holds the rights to the software created by its employees (i.e. software developers, researchers and/or staff). So, some formal (legal) steps are needed to arrange matters properly.

When these guidelines are followed and when the software is published, TU Delft disclaims its copyright, allowing software developers, researchers and staff to hold the copyright to their software and thereby having the right to apply one of the pre-approved licences when sharing software. The pre-approved open source software licences at TU Delft are Apache, MIT, BSD, EUPL, AGPL, LGPL, GPL, and CC0.

Steps:

  1. Determine if it is possible to apply an Open Source Software licence to your project (see diagram below).
  2. The waiver of TU Delft should be indicated in the software licence with the following text:

Technische Universiteit Delft hereby disclaims all copyright interest in the program “Name program” (one line description of the content or function) written by the Author(s).

[Name Dean], Dean of [Name Faculty]

  1. Assert your own, personal copyright (© YEAR, [NAME], [REFERENCE project, grant or study if desired]. The reason for waiving the copyright and having the software developers, researchers and staff file the copyright in their own name facilitates the use of copyleft licences
  2. Apply one of the TU Delft pre-approved Open Source Software licences in the format and form described in the licence text after stating, “This work is licensed under a [NAME and VERSION] OSS licence”.
  3. Make the software openly available (for instance in an online repository such as GitHub).
  4. Please consider acknowledging support from TU Delft and/or your funding provider.
  5. Register the software either in 4TU.ResearchData or in PURE.
Important

Please note that if the software is not published, and/or if the guidelines have not been followed correctly and/or if the software is not registered in PURE, then this ‘agreement’ is invalid and the software automatically falls under the legal copyright of TU Delft. This instantly nullifies the right of the software developer or researcher to apply for a licence and thus the open source software licence applied never came into existence. This works retroactively.

11.2 Decision tree for applying for a license

TU Delft staff members can apply for an open-source license according to the decision tree found in TU Delft Guidelines on Research Software: Licensing, Registration and Commercialisation.

Figure 1. Decision tree to guide software developers, researchers and staff on when they can apply an open source licence to their software (OSS: Open Source Software, IDF: Invention Disclosure Form). From: Bazuine, M. (2021). TU Delft Guidelines on Research Software: Licensing, Registration and Commercialisation. Zenodo. https://doi.org/10.5281/zenodo.4629635

11.3 Types of open source licenses

  • Permissive licenses aka copyright (e.g., MIT, BSD, Apache): These licenses allow users to do almost anything with the code, including using it in proprietary software.
  • Restrictive licenses aka copyleft (e.g., GPL, AGPL, LGPL, EUPL): These licenses require any derivative works to be open source and distributed under the same license.

11.3.2 Copyleft licenses

  1. GPL (GNU General Public License): One of the most widespread copyleft licenses. With the GPL license, any derivative work under this license automatically becomes subject to the same GPL terms, regardless of the size of the contribution. All future modifications and adaptions of code under this license is only compatible with this license and cannot be used in proprietary software.
  2. Derivatives from GPL (AGPL, LGPL, EUPL): From these, the EUPL license is somewhat more flexible compared to others as it can coexist with other open-source software licenses such as MIT, BSD, and Apache. For instance, if you integrate a portion of software that is licensed under Apache into a project governed by EUPL, that portion can retain its Apache license. In contrast, under the GPL, the entire codebase would need to be licensed under GPL.
Note

There are even instances when GPL licenses are incompatible with each other. For example, GPL-2.0 is incompatible with GPL-3.0. If a project uses GPL-2.0 you are essentially forced to use that license.

11.3.3 License compatibility

Figure 2. Compatibility of licenses. From: Bazuine, M. (2021). TU Delft Guidelines on Research Software: Licensing, Registration and Commercialisation. Zenodo. https://doi.org/10.5281/zenodo.4629635

Tip

Don’t forget to check whether your software’s dependencies have restrictions on re-use.

It is advisable to contact your faculty’s data steward regarding licensing questions. If your project involves complex legal considerations, particularly regarding intellectual property rights or compliance with licensing agreements, the Innovation and Impact Center should also be involved.

Further reading