Authors retain copyright of their contributions to ARTIQ, but whenever possible should use the GNU GPL version 3 license for them to be merged. Works of US government employees are not copyrighted but can also be merged. We've introduced a "sign-off" procedure on patches that are being sent around. The sign-off is a simple line at the end of the explanation for the patch, which certifies that you wrote it or otherwise have the right to pass it on as an open-source patch. The rules are pretty simple: if you can certify the below: Developer's Certificate of Origin (1.1 from the Linux kernel) By making a contribution to this project, I certify that: (a) The contribution was created in whole or in part by me and I have the right to submit it under the open source license indicated in the file; or (b) The contribution is based upon previous work that, to the best of my knowledge, is covered under an appropriate open source license and I have the right under that license to submit that work with modifications, whether created in whole or in part by me, under the same open source license (unless I am permitted to submit under a different license), as indicated in the file; or (c) The contribution was provided directly to me by some other person who certified (a), (b) or (c) and I have not modified it. (d) I understand and agree that this project and the contribution are public and that a record of the contribution (including all personal information I submit with it, including my sign-off) is maintained indefinitely and may be redistributed consistent with this project or the open source license(s) involved. then you just add a line saying Signed-off-by: Random J Developer <random@developer.example.org> using your legal name (sorry, no pseudonyms or anonymous contributions.) ARTIQ files that do not contain a license header are copyrighted by M-Labs Limited and are licensed under GNU GPL version 3.