I want to move from MIT license to a new one, with this goals to reach:

  • Leave the project free to use for individuals and small open source companies
  • Let commercial companies pay some money for using my software

And I have some questions about this plan:

  1. What license type should I choose?
  2. What kind of monetization strategy for commercial use should I choose? One time for company with unlimited use? Each time company uses software in its projects?
  3. Will the license have power only for new versions of the software? Or for the old versions too?
  • Hi IonDen. I've put this question on hold for the moment, because it's really asking far too much. You should think about breaking this up into multiple posts - you've already done most of the work by bulleting your points, so perhaps that would be a good start. You can edit this question down to be narrower, and post new questions for anything else you have, and you can either raise a custom flag for reopening when you're done, or drop into chat and ask there.
    – ArtOfCode
    Commented Sep 30, 2015 at 15:41
  • Won't the outlined restrictions make this incompatible with Free and Open Source licenses in general, and as such, offtopic? Commented Sep 30, 2015 at 15:54
  • @MichaelSchumacher Perhaps, perhaps not. See what some edits bring to it.
    – ArtOfCode
    Commented Sep 30, 2015 at 17:47
  • @ArtOfCode, hi. Tnx for mention it, really that was too much. I made it less complex
    – IonDen
    Commented Sep 30, 2015 at 19:41
  • Thanks, that's much better. We probably won't be able to help with your second question as this site is more about the open side of things than the commercial strategies, but 1 and 3 we can certainly answer. Reopened.
    – ArtOfCode
    Commented Sep 30, 2015 at 19:46

1 Answer 1


When you are looking for a license which forces some people to pay you but not others, you aren't looking for an open source license. The open source definition says:

No Discrimination Against Persons or Groups

The license must not discriminate against any person or group of persons.

No Discrimination Against Fields of Endeavor

The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.

That means we can not help you to find a license which does this, because that would be off-topic on this website.

But there might be a way to reach the goal you want while still keeping the project open source: dual licensing.

This is a business model used by many open source companies. Offer the software under two different licenses:

  1. Gratis under a copyleft license like the GPL
  2. For money under a proprietary license

In theory, both license models are available to anyone. But the commercial deal should include some additional perks which are important for large companies but secondary for private people and small businesses, like:

  • A support contract
  • A warranty
  • Additional components which are not GPL and help to integrate the software in a business IT infrastructure.
  • Permission to use the software in closed-source applications

The exact details of the deal (like pricing structure and whether to charge by use, by user, by cpu or whatever) are a business decision we can not really help you with unless we know your product and your market. Look at your potential customers and ask yourself what kind of deal would be acceptable when you were in their shoes. Also look at competing products and try to offer a slightly better deal than them.

Regarding your question about older versions: The older versions are out there under the MIT license. The MIT license has no revocation clause. That means the old versions stay out there under MIT and can still be changed and redistributed. There is not much you can do about it. But you will have a great competitive advantage against them: MIT licensed code can be integrated into GPL projects, but not the other way around. That means when anyone adds any new features or bugfixes to the old MIT version, you can take them and integrate them into the GPL version. But the GPL does not allow the opposite, so they can not integrate your updates into their version (unless they also switch to the GPL).

  • Thaks. That explains a lot.
    – IonDen
    Commented Oct 1, 2015 at 9:25
  • Great answer. Can you elaborate a bit more or provide a reference for "MIT licensed code can be integrated into GPL projects, but not the other way around"? I understand why the second part of that sentence is true, but not the first half. Commented Oct 3, 2015 at 17:46
  • @KevinKrumwiede the MIT license permits sub-licensing, but the GPL does not.
    – RubberDuck
    Commented Oct 6, 2015 at 22:13
  • References from the Free Software Foundation: 1. What does it mean to say that two licenses are “compatible”? 2. Expat License / MIT License
    – jkdev
    Commented Oct 16, 2015 at 5:57

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