By choosing a licence for your research software, you define the terms of reuse, and indicate what others are allowed to do with it.

Introduction

Publishing research software enables others to discover and reuse it. Unlicensed research software is automatically protected by copyright, but in that case, others are not allowed to use or build upon it. Open-source licences define the terms for legal use, modification, and distribution of software. Proprietary licences allow legal use but prevent copying, modification, and distribution of software.

Software licences

Software licences can be classified into different categories:

1. Open-source licence: a legal document that outlines how software can be used, modified, and distributed.

Permissive licence: most common licences that impose minimal restrictions, and the derivative work can be licenced under any licence.

Copyleft licence: a type of open-source licence that allows users to freely use, modify, and distribute software, with the condition that any derivative works are distributed under the same licence. 

Copyleft licence (strong): licensed software is not to be used as part of proprietary software, protecting the open source nature of both the software and its use.

Copyleft licence (weak): licensed software can be used as part of proprietary software.

2. Proprietary licence: software is ineligible for any copying, modification or distribution and ensures that ownership remains with the licensor.

Source image: Research Software Support eScience Center, CC BY 4.0

Open Source licences

Although WUR has no policy requiring the use of a specific software licence, WUR does recommend that researchers make their research software as open as possible. Additionally, research funders generally require software resulting from funded projects to be as open as possible. The most sought-after open-source licences are the MIT, Apache 2.0, BSD and GNU GPL licences. For a short description of these and other licences for software and code, have a look at the explanations by 4TU.ResearchData.

Choosing a licence – what to consider

Several factors should be considered when determining which licence will be best for your research software. As such, we recommend you review the following before choosing a licence for your research software: 

• Licences of the software developed by others you used or are linking to (the licence you choose must be compatible with the licence(s) of the used software).
• Who developed the research software and how intellectual property is arranged (e.g. internal collaborations within the WUR and external collaborations with other organisations).
• Whether it aligns with your research objectives and the needs of your research project.
• Whether the research software has commercial and/or utilisation potential (see below).

Note: if research software has commercial potential, then it should be disclosed by completing a Software Disclosure Form (SDF) and Value Creation Form (VCF). More information can be found in the Guidelines on Value Creation with Software and Data in this article. 

Choosing and comparing tools

Several online applications can help you choose a licence:

• Choose a Licence
• Open Licence Helper (compare licences)
• Wikipedia (compare licences)

Note: After you have chosen a licence for your research software, you do not have to write the licence texts yourself; they are available via the Open Source Initiative: Licenses – Open Source Initiative.

Support

Do you have any questions? Feel free to contact the Copyright Information Point. You can send an email to the Copyright Information Point.