Contributing developers to HRE must agree to release their code by default under the GNU Affero GPL, and contributors to the website and project documentation must agree to release their contributions under CC BY-SA 4.0.

We ask only for a licence, not for an assignment of your copyright.

Signifying your agreement

To ensure that all contributions to the HRE project are and will always remain open and freely reusable, we require all contributors to confirm agreement to the following. One-off variations for special circumstances may be approved only by prior written agreement from History Research Environment Ltd (‘HRE Ltd’).

Once you have been accepted as a volunteer contributor to the HRE project, you will be asked to signify your agreement to these terms by email.

To offer your assistance as a volunteer, please visit our volunteering page.

Legal agreement

This is a legally binding agreement.

This agreement is made between me (the contributor) and HRE Ltd.

In consideration of the privilege of contributing content as a volunteer to the HRE project:

  • I confirm that all of my contributions will be entirely my own work and that I will not infringe any third party copyright by reuse of third-party content. I will not knowingly infringe any non-copyright intellectual property rights or the contractual rights of any third party. If I become aware of any relevant third party rights I will promptly advise HRE Ltd.
  • Any contributions I make to this wiki, to the HRE project website or to any HRE project documentation shall, by my act of posting or incorporation into project documentation (or by my agreement to do either of those things), automatically and without further formality be released under an irrevocable Creative Commons Attribution-ShareAlike 4.0 International licence (‘CC BY-SA 4.0’).
  • Any contributions I make to the HRE codebase shall, by my act of incorporation into the codebase (or by my agreement to such incorporation), automatically and without further formality be released under an irrevocable GNU Affero General Public Licence or any later version (the ‘GNU Affero GPL’).

I understand that I am not being asked to transfer ownership of my copyright. I will retain copyright in my contributions, and I may re-use or re-license my contributions at any time (subject only to the terms of the copyright licences mentioned above).

This agreement is subject to the laws of England and Wales, and the courts of England and Wales shall have sole jurisdiction.


  • These notes are not part of the agreement

If any part of your proposed contribution is not entirely your own original work, we need to know about it in advance so that we can if need be make special arrangements before accepting it. This would apply, for example, if you wanted to incorporate a routine which is subject to some other licence or which you believe to be in the public domain.

It is acceptable to make use of non patent-encumbered generic high-level algorithms or coding practices, but making use of any third-party code, even with additions or modifications, runs the risk of copyright infringement.

In appropriate cases it may be possible to accept non-original content and to make special arrangements to vary this contributor agreement. However, in the absence of prior written agreement from HRE Ltd the above terms will apply.

If you need to discuss a variation to this agreement for any specific contribution please contact us.

See also