Copyleft License with CLA

Some projects, before accepting external contributions, will ask contributors to hand-over relicensing rights. This is often achieved by the user agreeing to a Contributor License Agreement (CLA). This allows the accepting project author to change the license of those provided works in the future, beyond the default FOSS license which the project is already using.

When combined with a strong copyleft license, this can result in a significant (and often unmentioned) imbalance of rights between users and the project author, since that author has rights to relicense & combine with non-FOSS works in ways which any other user cannot (at least without permission).

While projects with permissive licenses may also have such rights-handovers, it’s usually not so much of an issue as the abilities & rights gained are often minimal compared to what the project license provides by default.

Such handover of rights may not be a big issue to many, as it does not impact the project’s current status as FOSS, but it can be an indicator of potential future license changes and reflect the author’s thoughts (and lack of assured commitment) to free software.

One side effect of such a rights-handover requirement, is that projects which use this cannot directly accept/take code shared from forks, or that published via modified software versions without permission. This means that community forks (without such rights handover requirements) can share code freely between each other, potentially enabling greater community momentum over the original project.