I have been searching for an open source license to use for my project. There are many little things i would like to have but only one thing that truly matters - I don't want anyone to use my projects libraries or the project itself to build something that they can then patent.

This is because the project is a charity about supplying free services if they are deemed essential or a basic human right. So it will not do if a third party creates, for example, a medical tool that they charge for, and then prevents us building a free alternative.

On the other hand, we do want a third party to do this if they themselves are looking to give their service for free as it reduces our work load. I could talk you through licenses I have considered thus far but perhaps its better to let you answer free of influence.

  • 1
    It seems to me that your third paragraph has some incorrect assumptions - just because they can't patent it doesn't mean they can't charge you for the software (or use of a hosted service), right? Jan 18, 2017 at 19:01
  • It seems odd to me that it went unmentioned that if you publish your code as open source (especially using a public service like Github/Gitlab, which has strong time-stamping), and someone later creates a patent based on that code, any attempt to enforce that patent on you is likely to have issues since you have a good chance of showing prior art (thereby invalidating the patent entirely). There is still some risk, based on derivative works, but choosing a open source license with patent protections likely would cover that. Of course, speaking with a lawyer would not hurt. IANAL/IANYL
    – xzilla
    Aug 5, 2019 at 22:55

3 Answers 3


"Using copyrighted material to build something patentable" doesn't describe a concrete prohibition. In reading your source code, the other guy might gain insight into how to automate a widget-press, which could in principle be patentable. Copyright law allows you to restrict how others copy your code, but does not allow you to protect underlying ideas. In a sense he has used your product to build something, and in another sense he hasn't – you would need to describe the prohibited uses with greater precision. The question of whether something is "patentable" is pretty much determined after the fact – if a patent is granted, it was patentable. Perhaps you have in mind something like "if you use it, and get a patent, then you grant us permission to make a competing object that we will distribute for free", which pretty much obliterates the point of a patent.

You can't use copyright law to restrict manufacturing. Some manufactured goods contain actual software, in which case you can prohibit copying your code into the device. A non-commercial license would do that, and more (it would also prohibit incorporating your code in a non-patentable program). If you want to get more complex than that, you need to hire an IP lawyer.


There is no free or open source license that would prohibit patenting.

This would go against the spirit of open source in general and would be a restriction in usage which would make the license non-free.

There are however several licenses that speak about patents.

  • Some licenses provide for an explicit patent licenses such as the Apache 2.0,
  • Some licenses are muted on the subject and may provide implicit grants (such as the BSD licenses)
  • and licenses some contain "patent non-assert"-like terms and non-assert terms like the GPL 3.0:

To prevent this, the GPL assures that patents cannot be used to render the program non-free.

So if you want your code to be licensed under a mainline, well-known and community-accepted license, you should consider using an existing licenses such as the Apache 2.0 or the A/L/GPL 3.0 licenses.

Otherwise, you could create your own non-free, proprietary license with the risk that none will ever consider using your software because of its uncommon terms.


Hire a lawyer to draft a licence that does exactly what you want.

As a suggestion, start with a Creative Commons Attribution-Share Alike and add a proviso that you must be given a perpetual, non-repudiable, royalty free licence to any patents that utilize your software.

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