# Contributing

Contributions are welcome.

Contributions can be done via [GitLab merge request](https://gitlab.com/slepc/slepc/-/merge_requests) or via patches (`git send-email` or `git format-patch`) sent to <slepc-maint@upv.es>. The preferred way of accepting contributions is via merge requests, as described at [PETSc Developer’s Documentation](https://petsc.org/release/developers/). If you are planning a large contribution, we encourage you to discuss the concept with us and interact frequently to ensure that your effort is well-directed. The name of the contributors will be acknowledged in SLEPc's documentation and website.

SLEPc is distributed under a [2-clause BSD license](../documentation/license). The act of submitting a pull request or patch (with or without an explicit Signed-off-by tag) will be understood as an affirmation of the following:

> Developer's Certificate of Origin 1.1
>
> 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.
