Copyright policy

GLEP 76 defines copyright and license policies for Gentoo Linux.

Every Gentoo project must abide by the Gentoo Social Contract and release its work under one or more of the following licenses:

The GNU General Public License, version 2 or later (GPL-2+)
The Creative Commons Attribution-ShareAlike 4.0 International License (CC-BY-SA-4.0), only for documentation
Any GPL-compatible free software license

Exceptions for other (GPL-incompatible) free software licenses may be granted by the Gentoo Council on a case-by-case basis.

Certificate of Origin

Per GLEP 76, you must sign-off all your commits to any Gentoo-hosted repository with accordance to the copyright policy.

When committing work authored by someone else, e.g. a Bugzilla patch, or GitHub pull request, a sign-off from the original author is always strongly recommended, in order to indicate that the author acknowledges Gentoo's copyright policy. However, it is not mandatory for every case. Please refer to the example list below when determining whether a sign-off from the original author is, or is not required. The list below serves as a general guideline.

General guideline

Flowchart showing the steps for accepting a contribution

When can a contribution be accepted?

When signed off by its author (i.e. with a Signed-off-by line):

Can be accepted, because the author has confirmed that it is under a free software license. The committer adds another Signed-off-by line and certifies the commit under point 4 of the Certificate of Origin.

Note: Use common sense here, especially if you don't know the contributor. If the contribution was taken from somewhere else and the contributor doesn't have the right to distribute it under a free software license, you as the committer might get into trouble. So in this situation, do your best to check repositories for matching code, and whether they hold any special copyright claims.
When not signed off:
1. If the contribution is not of "legally significant" size (by the FSF's 15-lines rule of thumb):
  
  Can be accepted. The committer adds a Signed-off-by line and certifies the commit under point 2 of the Certificate of Origin.
2. If the contribution is of significant size, and
  1. with an independent indication of its license (e.g. copyright and license notices in the file's header):
    
    Can be accepted. The committer adds a Signed-off-by line and certifies the commit under point 2 of the Certificate of Origin.
  2. without any other indication of its license:
    
    Can not be accepted. There's no indication that the author has released their work under a free license, therefore it must not be distributed by Gentoo.