Contributor License Agreement

Summary and scope

It may seem self-evident that contributing to a project distributed under an open-source license is an implicit permission to anyone for using the contributed code. However, a formal Contributor License Agreements (CLA) makes contribution terms explicit and provides the project maintainers a record of your agreement to those terms.

A wide range of terms exist in other CLAs, including waiver of moral rights, consequential damages waiver, as-is disclaimer, etc. For this project, we follow the more bare-boned GitHub CLA, which focuses on the three most important clauses: copyright, patent, and source of contribution.

In short, by signing this Contributor License Agreement, you confirm that:

  1. Anyone can use your contributions anywhere, for free, forever.
  2. Your contributions do not infringe on anyone else’s rights.

Definition of terms

The following terms are used throughout this agreement:

  • You - the person or legal entity including its affiliates asked to accept this agreement. An affiliate is any entity that controls or is controlled by the legal entity, or is under common control with it.
  • Project - the repositories message_ix and ixmp, and any derived repositories, projects, or software/code packages.
  • Contribution - any type of work that is submitted to a Project, including any modifications or additions to existing work.
  • Submitted - conveyed to a Project via a pull request, commit, issue, or any form of electronic, written, or verbal communication with GitHub, contributors or maintainers.

2. Grant of Patent License

Subject to the terms and conditions of this agreement, You grant to the Projects’ maintainers, contributors and users a perpetual, worldwide, unlimited in scope, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this section) patent license to make, have made, use, offer to sell, sell, import, and otherwise transfer your contributions, in whole or in part, where such license applies only to those patent claims licensable by you that are necessarily infringed by your contribution or by combination of your contribution with the project to which this contribution was submitted.

If any entity institutes patent litigation - including cross-claim or counterclaim in a lawsuit - against You alleging that your contribution or any project it was submitted to constitutes or is responsible for direct or contributory patent infringement, then any patent licenses granted to that entity under this agreement shall terminate as of the date such litigation is filed.

3. Source of Contribution

Your contribution is either your original creation or based upon previous work that, to the best of your knowledge, is covered under an appropriate open source license. You assure that you are legally entitled to submit your contribution and grant the above license, or you have clearly identified the source of the contribution and any license or other restriction (like related patents, trademarks, and license agreements) of which you are personally aware. If your employer(s) or employee(s) have rights to intellectual property that you create, you represent that you have received permission to make the contributions on behalf of that employer/employee, or that your employer/employee has waived such rights for your contributions.

Should the licensor be held responsible for any violation of intellectual property right in relation to your contribution, you shall be fully liable for damages that may arise.

Reference and License

This Contributor License Agreement and the introductory text is adapted from the GitHub Contributor License Agreement, Version 298f3afd updated August 9, 2017. GitHub granted a CC-BY-4.0 License to IIASA to use and modify the text of the CLA.