Let's consider following scenario:

  1. Person A creates a piece of software and releases the source code under a permissive license, let's say MIT
  2. Person B downloads that piece of software and uses it accoridingly to MIT license.
  3. As an owner and holder of all the right Person A decides to change the license from MIT to other license, especially less permissive one like GPL. For simplicity let's assume that there were no contributions to the piece of software in the meantimy by any other people.
  4. Person A releases a new version of the software

In that scenario what happens to the rights given to the person B?

  • Is person B allowed to still use the last version released before the change of the license under the old license (MIT) and all the versions released after change of the license as new license (GPL)?
  • Is the entire piece of software licensed MIT or GPL after the change?
  • Basically can rights given by license be revoked by the owner?
  • 2
    – tkausl
    Commented Feb 17, 2016 at 7:29
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  • 3
    Rights given by license cannot be revoked. (Otherwise, any single contributor could kill Linux at any time.) What you describe is dual-licensing, which basically means the software is available under two different licenses, and as a user you have to choose which license to follow. Person A could decide to only release new versions of the software under the new license, but the original version would remain available under the old license, and could be revised by other developers, basically leading to a fork.
    – JacquesB
    Commented Feb 17, 2016 at 7:43
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    Rights given by license cannot be revoked. unless the licence includes that they can -- which the MIT doesn't.
    – TZHX
    Commented Feb 17, 2016 at 7:50
  • @TZHX: Good point, although I assume no open source license allows this.
    – JacquesB
    Commented Feb 17, 2016 at 7:56

1 Answer 1


IANAL, but the guy who wrote this article is.

The conclusion he makes is that until it has actually been through court and precedents has been set, it is not clear that a license cannot be revoked. And the really big problem is that any decision might be dependent on the jurisdiction. You could imagine a situation where a user is in the US uses a piece of software made in the EU, the license is revoked, but US court says it cannot be reworked and the EU court says it can.

One of the main points is that there is not established a contract, because the user of the software has not bought it. If there were a specific contract between the copyright holders and the users (even without transfers of funds), that point would likely go away, but that requires a contract in each specific case.

So the current answer is, that even if it states in the license that it cannot be revoked, then it is not certain that it cannot, because of the lack of a specific contract.

  • If there were a specific contract between the copyright holders and the users (even without transfers of funds)... - Software license agreements have the five attributes of contracts (offer, acceptance, consideration, mutuality and capacity), and courts in the U.S. and Europe have ruled repeatedly that the terms of license agreements are enforceable as contracts. Maybe Australia is different, but I doubt it.
    – Blrfl
    Commented Feb 17, 2016 at 12:39
  • Are you sure that is for the use of source code as well and not only for programs? If I install e.g. TortoiseSVN I agree to a license agreement by clicking on a button. How does that compare to me being given source code under GPL or MIT from a person who is not at all affiliated with the copyright holders of that software? If you can find court cases to this effect I would be glad to see them.
    – Bent
    Commented Feb 17, 2016 at 12:52
  • Intellectual property is intellectual property whether it's source or binary. The copyright holder still holds the rights and dictates the terms whether you got it directly from him or a third party who's allowed to redistribute it under the terms of the license. Most licenses make clear what constitutes acceptance. I'll dig up a couple of cases if I can find a few additional minutes, but they're not hard to find with some well-applied Google-fu.
    – Blrfl
    Commented Feb 17, 2016 at 14:18

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