What requirements do you have to complete to change your software license?

Question

Say you published your work under the GPL, but after a while you realized that it would be better to publish it under another incompatible GPL? What options do you have? You (or your team), as an author, were allowed to simply change the license? Or do you need permission from each participant, each error seeker?

I know that some teams change licenses for their software, but I did not find much information on how to go through this process. I do not want to close some paths to my software or definitely get stuck inside one license.

Answer 1

If you have merged with bug fixes, obtaining permission from each copyright holder may be difficult or impossible.

An alternative would be to fork your project and remove all the code that you (or your team) do not have rights to use copyright. You can then reuse this spotless code under the new license of your choice. Please note that after the code has been combined and worked on, as it can be difficult to prove which code belongs to those to whom you should contact a lawyer.

Some projects also require all participants to give up copyrights to project owners when sending patches, etc. This greatly facilitates the process of changing the license.

Answer 2

You need permission from each copyright holder. Please note that copyright holders do not have to be participants, they could acquire copyrights in other ways.

To protect yourself, you usually get this written permission signed by the copyright owner - this is usually called copyright disclaimer. This usually includes explicit evidence that the copyright owner is waiving his rights to his software copyright.

Once you have rejected the file, you can change the license, but consider it necessary.

Answer 3

Keep in mind that you have already released your code under the GPL, and each recipient of this code has the right to send the code to everyone they know, still under the GPL. You cannot return the rights that you have already given them. Since you (and other copyright owners) are the original owners of the code, you can change the code and redistribute the new version under a more restrictive license.