There is an opensource project that I started some years ago and I still maintain it. This project is licensed under the BSD (3 clause) license and at the moment I am the sole copyright holder and contributor of the project.

Every source file contains this copyright info:

// Copyright (C) 2009-2016, <my name>.
// All rights reserved.
// Code licensed under the BSD License.
// http://www.<projects_website>.org/LICENSE

Here is a link to the BSD license.

Recently someone expressed his interest in contributing and I would like to know what is the best way to handle contributions so that everyone is happy. Copyright transfer agreement? Adding new copyright co-owners in files. Something else? What kind of changes I'll need to make to the license and the source files' copyright notice?

2 Answers 2


Ask the contributor to add their contribution under the same license. Nothing is lost (you still can take it as a basis for closed source).

I'd make sure to add a CONTRIBUTING file somewhere in your version (and show it prominently) stating that only contributions under the above license will be accepted, and that contributor affirms to have the right to contribute under those conditions.


There are many ways to handle such things.

Copyright transfer is not well seen by external developers, and with a BSD license I think it is also not worth the effort: it is anyway difficult to lock further the derivation of work.

So if the contributor will do substantial work in a file, I would add his copyright line in that file. Some project prefer to have an AUTHORS file to put the name and copyright holder of all the modifications. Try not to mix different licenses in the same file.

IMHO it is important to use a control version system, so to track the contribution of the different authors. There is no need that all (or any) contributors will use it, but you should track it. In this way you will have much less work in case of splitting the project (e.g. creating a library), changing licenses, etc. [e.g. git can track who contribute every line of code].

  • I was thinking about two modifications. (1) A contributor copyright license agreement. This website has a template selector.harmonyagreements.org where the contributor will be the copyright owner of his modifications but he will have to license his contribution to me. (2) Modifying the source files to write "Copyright <year> <my name> and contributors". Will that work? Mar 1, 2016 at 15:15
  • Yes.But do you really want a license from contributors? Why? (BTW the Harmony is not well seen in general) Mar 1, 2016 at 20:51
  • I am not sure if a license from contributors is what I want. What I really want to avoid a situation where a contributor wakes up one morning and asks me to remove his contributions from the project. Mar 2, 2016 at 8:51
  • 1
    The BSD license allows you (and any other person) to keep the code. The extra license could be useful in case of re-licensing (compatibility with new license, other code), but usually they are not so welcome, because they get too much power to a corporation. For a BSD license I don't see any problems. Just make sure that contributions need to be BSD licensed, and use git (or over control version system) to save code change and the email of contributor ("git am" is very useful) Mar 2, 2016 at 9:28
  • The source is in a git repo so there will be bookkeeping. But how can I make sure that contributions will be BSD licensed? Mar 2, 2016 at 13:29

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