In the topic Appropriate licence for later merging back, one of the desired criteria was,

  1. I want to be capable to merge any derivatives back [...] from somebody who made modifications [...].

It attracted answers like this:

I don't believe any FLOSS license requires you to publish all changes (i.e., forbidding private derivatives), if that's what you mean. If you're talking about published derivatives, then any copyleft license would require those derivatives to be published under a license that would allow you to merge them back in. But note that they retain copyright for their own changes.

There's something similar in this answer to a different topic:

you have to avoid Being forked into oblivion by a more powerful contributor, so only a license with a strong copyleft makes sense.

My question is related to these, maybe a bit simpler. Assume the following scenario:

  1. I write some software
  2. I publish it with a license (e.g. GPL)
  3. Someone else takes the software, modifies it, and distributes it to their customers

Do I (the original author) have any right to see the modification? Am I even notified that there is a notification? Would I have to be one of their customers (which might be too expensive) to see their modification?

My reading of the GPL implies that I would have no right to see their changes, because it says ...

"You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy. "

... but doesn't say that the original author/licensor is entitled to come into possession of a copy.

If not the GPL, is there any way to license software (especially, is there any standard license) such that the original author is entitled to see any changes that are made or used or released?

In summary, is there any license intended to guarantee that the original author (and not just users of the modified software) is one of the people who has access to subsequent changes, the latest and greatest copy?

  • 1
    Under the GPL, no, definitely not; downstream modifiers are allowed to keep their modifications private, or share them with a specific limited set of people which need not include the original author. An interesting related question is whether such a requirement would still be allowed under the FSF's four freedoms or OSI's Open Source Definition.
    – apsillers
    Jul 28, 2017 at 17:47

2 Answers 2


No. And it's not a good idea anyway since the whole idea of Free Software is to support a proliferation of authors and consequently rightholders, and their rights are inheritable and transferable.

So if Free Software is supposed to remain manageable, any duties of the user/distributor must be meetable by dealing with the tangible copies appropriately without having to identify and/or contact every author. If you try to make a license dial home, you immediately get into the problem that for a "Public" license (where the original authors don't hold special rights over additional authors) the requirements bog down the software as it garners new contributors.


Something like this may be a (partial) solution: Collective Code Construction Contract (C4)

The software is GPL but there's a "contract" that people will develop it in github (i.e. on a common "platform").

It seems to me that, with the software being GPL, people can create a hidden fork of it.

But for people who want to collaborate, the "C4" provides a protocol for that.

I think that e.g. WebKit might be similar: i.e. that people can have private forks of it. I'm not sure what the disincentive is (i.e. what the incentive is to not have a private fork) -- I think the incentive might be that, if you own a private fork, then it's your burden to merge every latest and greatest change into your fork.

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