I am planning to write some financial modeling software targeting enterprises. It will be based on an existing open-source project that already has a BSD-3 license. I do not own the copyright to the original project but will be using it to create my derivative work. I would like to keep my project open-source as well but I can imagine a situation where a company wants to hire me to make additional modifications or request development of special features specifically for their business. They would likely require such modifications to be closed and proprietary especially if it pertains specifically to their business.

  1. In that situation, am I allowed to issue a separate license to the client since I am the copyright holder for the derivative work? Is it possible to keep that version of the software closed source?
  2. If I accept contributions from the open-source community, I assume there would then be other copyright holders to different parts of the software. Do I need to acquire copyright transfer from contributors? Is that even possible with the existing BSD-3 on the original work?
  • Would the company hiring you be selling/releasing these modifications, or just using them for their own purposes? Commented Jan 7, 2017 at 2:32
  • They would be using it for their own purposes.
    – uclatommy
    Commented Jan 8, 2017 at 2:17

1 Answer 1


The answer to the first question is clearly yes. You own the copyright and can issue copies of your work under different licenses.

You would need the approval of any joint copyright owners (people who have contributed to the project but have not transferred copyright to you) to change the license, but it's still permitted to incorporate BSD-licensed material in a more restrictively-licensed or closed-source project, so long as the requirements of the BSD license are met (mainly, keep the attribution and original disclaimer intact in the source).

You can probably get more detailed answers from http://opensource.stackexchange.com

  • Don't the original work's copyright holders also have claim to the derivative work? I'm changing like 75% of the code, but since it is based on a pre-existing project, I have to preserve the original BSD-3 license and the original copyright holders, right?
    – uclatommy
    Commented Jan 8, 2017 at 19:39
  • @uclatommy yes, that's why you need their approval if you want to change the license. Inherent in the license is their approval for you to use and redistribute the code freely as long as you keep the original copyright notice and license intact. Commented Jan 8, 2017 at 20:44

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