This article is taken from our Open Source Hardware brochure.
A licence makes it clear under which conditions the licensed knowledge may be used. An open source licence ensures trust in your intentions to make knowledge openly available and protects contributors, users and you from misunderstandings.
A collaborative development process is only possible with an open source licence as a common legal basis.
For hardware, we recommend a variant of the CERN OHL v2.0. It has been written explicitly for hardware, continues to be maintained and, like many open source licences
like many open source licences, is available in three variants.
Various open source licences
Permissive
Permissive licences give people the greatest freedom to reuse the project. In most cases, only the author must be named. Here are a few examples:
- MIT licence
- CERN Open Hardware Licence Version 2 – Permissive – CERN-OHL-P-2.0
- Creative Commons International 4.0 – CC BY 4.0
Copyleft
Copyleft licences require contributors to place all new versions of the project under a copyleft licence again.
under a copyleft licence. A distinction can be made between “weak” and “strong” copyleft licences. “Strong” copyleft licences require that everything relating to the project must be placed under the same licence, while “weak” copyleft licences only require that the project itself must be placed under the same open source licence. Here are a few examples of copyleft licences:
- GNU General Public Licence Version 3.0 – GPL v3 (for software)
- CERN Open Hardware Licence Version 2 – Weakly Reciprocal -CERN-OHL-W-2.0
- CERN Open Hardware Licence Version 2 – Strongly Reciprocal – CERN-OHL-S-2.0
- GNU Lesser General Public Licence Version 3 – LGPL v3 (for software)
- Creative Commons Share Alike International 4.0 – CC BY-SA 4.0 (universally applicable, images, texts, videos, etc.)
Use of an open source licence
If you decide to place your project under an open source licence, you should name this licence correctly and mention it in a prominent place in the project.
You should also make it clear which parts of the project are covered by this licence – does it apply to the entire project or only to certain parts? There is nothing wrong with mentioning the licence several times in the documentation.
For each licence you use, add a text file with the entire licence text to your project folder. You can find the text on the licence providers’ websites. For CERN-OHL you can find the texts here.
Sources
If you want to find out more, you can find further sources on this topic here:
https://choosealicense.com/
Weinberg, M. (2015). Licensing of Open Source Hardware. In: Gibb, A., Adabie, S., Baafi, E., Bolton, M., Bradford, K., Levine, G., & Abadie, S. Building open source hardware: DIY manufacturing for hackers and makers. Addison-Wesley
A long list of open source licences can be found at https://spdx.org/licenses/. All licences that are FSI or OSI “approved” there also meet the requirements of DIN SPEC 3105, the DIN specification for open source hardware.
