Looking at https://choosealicense.com/appendix/, we can see that there are a number of licenses that provide patent troll protection, and there are also a few licenses that that do not require attribution (CC0, Unlicense, WTFPL).

However, there does not seem to be any licenses that I can find (on that list or elsewhere) that both protect against patent trolls and doesn't require attribution. does anyone know if such a license exists?

If not, is there some reason why the two are necessarily incompatible with each other such that no license could possible exist that provides both?

If they are mutually exclusive, is there any reason I wouldn't be able to dual-license my software under Unlicense and Microsoft Public License (to effectively create a scenario where no one needs to provide attribution, but the code is also offers protection against patent trolls?

As a software engineer, I want a way to create projects that have the lowest barrier possible, for any type of user. However, when using CC0/Unlicense/WTFPL I have found that some companies are unable to use my software because it doesn't provide patent protection. I would like to use a license that offers that protection while also not requiring that users go through the burden of attribution (which can be a bit of a pain when you actually follow through with it).

  • 1
    you may want to find out how to minimise the attribution required by Apache 2.0 license (e.g. leaving out the CONTRIBUTORS file)
    – lofidevops
    Commented May 23, 2017 at 12:42

2 Answers 2


By patent troll protection, I take it you refer to what the linked site expresses as "This license provides an express grant of patent rights from the contributor to the recipient". It is going to be very difficult to craft a licence that provides that protection but does not even require attribution, because of the problem of derivative works.

Suppose that A makes a piece of software, Z, which (s)he releases under such a licence to B, who removes A's attribution and makes a derivative piece of software Z2, which (s)he releases to C under that same licence.

Does C still benefit from A's patent covenant? C will want that to be the case, as if Z needed that covenant to be usable, it is very likely that Z2 will also. But Z2 contains no record of A's covenant, and if A's patents are later acquired by a troll who then files suit against C, good luck in persuading a court that this piece of software that makes no mention of A or his/her covenant can somehow nonetheless benefit from it.

If your clients desire patent protection, then in order for that protection to be meaningful, they are likely to need a licence that imposes some other obligations on them, even if only the obligation to keep the covenant intact. Oh, and IANAL/IANYL.


First things first, I know almost nothing about law, so don't follow my advice blindly and check with someone who does know.

Once you dedicate some work to the public domain, I assume you can not claim patent rights to the covered work.

To ensure that all contributers to the code does the same, e.g. Unlicense recommends and SQLite enforces that all contributers accompany all patches with a phrase that dedicates that patch to the public domain. With extra requirements from employees contributing in capacity of some formal organization. SQLite requires that a written a copyright release signed by a company officer is mailed to them.

The phrase used by them is:

I dedicate any and all copyright interest in this software to the public domain. I make this dedication for the benefit of the public at large and to the detriment of my heirs and successors. I intend this dedication to be an overt act of relinquishment in perpetuity of all present and future rights to this software under copyright law.

Further more SQLite offers to sell a license for a hefty fee if someone still insists on something more tangible. My guess is that they only offer this option since they have written consent from all contributers that everything is dedicated to public domain.


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    You mention SQLite but their license/public domain dedication doesn't mention patents at all. Copyright and patents are completely separate kinds of intellectual property/immaterial rights. It is not immediately obvious that relinquishing copyright by dedicating a work to the public domain would also implies a patent grant. I think it's therefore safest to assume no such implicit patent grant exists.
    – amon
    Commented Dec 14, 2017 at 14:00
  • If that is true, would "unlicensed" be better? As their first line in the license states that the software is "[...] is free and unencumbered [...]" as "unencumbered" means "not having any burden or impediment"/"free of debt or other financial liability" and further more having anyone contributing to the software add a waiver/phrase stating that the patch is released under "The Unlicense" as well. Since the unlicense explicitly states that the software is free and unencumbered. Once again, someone with better knowledge in the subject is encouraged to reply to this.
    – Ale
    Commented Dec 17, 2017 at 22:04

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