Contributor License Agreement


A Contributor License Agreement defines the terms under which intellectual property has been contributed to a company/project, typically software under an open source license.

Rationale

CLAs can be used to enable vendors to easily pursue legal resolution in the case of copyright disputes, or to relicense products to which contributions have been received from third parties. CLAs are important especially for corporate open source projects under a copyleft license, since without a CLA the contribution would restrict the guardian as well.
The purpose of a CLA is to ensure that the guardian of a project's outputs has the necessary ownership or grants of rights over all contributions to allow them to distribute under the chosen license. In some cases this will mean that the contributor will assign the copyright in all contributions to the project owner; in other cases, they will grant an irrevocable license to allow the project maintainer to use the contribution. CLAs also have roles in raising awareness of IPR issues within a project.

Users

Companies and projects that use CLAs include:
The Canonical Contributor Agreement was a Contributor License Agreement required by Canonical Ltd for all contributions to many projects established by Canonical.
In it, the contributor assigned copyright to Canonical and at the same time Canonical gave the contributor "a world-wide, non-exclusive, royalty-free and perpetual right to use, copy, modify, communicate and make available to the public and distribute, in each case in an original or modified form, the Assigned Contributions as wish."
Canonical started Project Harmony "...to assist organisations which use contribution agreements by providing standardised variable templates with clear and concise explanations...."
As of August 2011, Canonical is requesting contributions be licensed under a Harmony Contribution License Agreement, rather than the copyright being assigned to Canonical. With the Harmony CLA, "the contributor gives Canonical a licence to use their contributions. The contributor continues to own the copyright in the contribution, with full rights to re-use, re-distribute, and continue modifying the contributed code, allowing them to also share that contribution with other projects."
Projects requiring contributors to sign this agreement include:
uses Free Software Foundation Europe's Fiduciary Licence Agreement of which states in section 3.3:
However, it is optional and every contributor is allowed not to assign their copyright to KDE e.V.