[License-discuss] Can a contributor take back open source code ? - Yes, if he has not signed over the copyright.

From: informator
Date: Mon May 13 2019 - 01:15:59 EST

Hello Kevin.
but there is no path which would force the project to do so.
This is incorrect.

If the contributions were legitimately provided under an OSI-approved (or similar) license, the license cannot be terminated for convenience.
This is also incorrect. Free non-exclusive licenses can be terminated at-will by the copyright owner. A non-exclusive license, in and of itself, confers no enforceable rights against the grantor without being merged into a contract - regardless of whatever assertions are made in the text.

The very quality that makes opensource attractive makes any attempt to create a mutually enforceable agreement an artifice - and one that will fail.

(And, Yes I am an attorney)

I have a "not easy" question: is it possible for a contributor to remove his contributions (code, translations, ...) from an open source project?

In short: Yes the copyright holder can do just that in most cases we see in the wild (where there is no copyright assignment and the licensees are free-takers).

It seems to the policy of the FSF, SFLC, etc to claim to you that Illusory Promises are enforceable in the US courts, or to claim that obeying a preexisting legal duty is valid consideration for a mutually enforceable agreement (contract). Obviously you have an inkling to the contrary since you are asking this question. Your suspicion is well founded, as consideration, contrary to what interested parties may want you to believe, is still generally a requirement for a promise to be held enforceable, in the US.


Assuming: Contributor has not signed over his copyrights, and the entity did not pay consideration to the "contributor":


Free Non-exclusive licenses are revocable.

For a promise not to revoke or to revoke only under certain circumstances to be binding against the grantor he must have received some bargained-for consideration in exchange.

"Nothing" is not valid consideration.

Offering what you are trying to contract for as "consideration" for that very contract is not valid consideration.

Obeying a pre-existing legal duty (not violating the copyright holder's copyright) is not valid consideration.

You can read a lengthy explanation for the lay person here:
(and it covers the 9th circuit
Artifex case and 9th circuit Artistic License case which some people
will try to make you think invalidates your proprietary rights)
or here:

Note: If you would like a nice expansive legal paper to read on this
issue, Sapna Kumar's paper is good:

And, if someone do that, is it possible for the project to continue to maintain the previous version, thanks to the license? (I mean, before the deletion)

No. Once the license is revoked, if the licensee cannot show that it has an attached interest (ie: a valid contract), by law the licensee no-longer has permission from the copyright owner to use/distribute/modify/etc the work of authorship. They may beg the court under equity for some accommodation, of course.