Is there a short weak (or strong) copyleft license?

I like the GPL v3. The way that all its different sections interlock is quite poetic. However, this beauty comes at the cost of it being near impossible to understand. In licensing things I would like to be able to understand at least one of the licenses that I use. I was wondering if there are any short, permissive software licenses ideally consisting of only a weak copyleft clause that I could dual license under.

The fair license gives me hope that this must be possible, but I have not been able to find or make a short copyleft license.

I have looked at the Mozilla Public License, but it too is quite long and complicated.

This was my effort to write a short, weak copyleft license:

This datum may be used if distributed versions of the datum clearly direct users towards the source form of all files utilizing the datum clearly released under this license or this license and second compatible and more restrictive license that does not include terms that have never allowed by either the OSI or FSF or been contained in this license (except all patent provisions which may be changed to that of any license approved by the OSI or FSF and compatible with the GPL v3 regardless of how they compare to those of this license) and is compatible with the GPL v3 and the source form of all files utilizing the datum are available in a reasonable manner for no more than the cost of distribution and a nominal fee and without unreasonable delay; each contributor hereby grants every entity an irrevocable, unconditional, world-wide, royalty-free, non-exclusive patent license to make, use, sell, offer for sale, have made, import, and otherwise transfer either its contributions or the combination its contributions and those of others.

  • define "short" and "weak"
    – Trish
    Commented Nov 14, 2023 at 13:58
  • 2
    Required reading at this point: How can a "crayon" license be a problem? Commented Nov 14, 2023 at 21:05
  • 1
    I notice that your license doesn't actually give anyone permission to distribute the work, prepare derivative works, or distribute derivative works. Also, it's not clear what the whole 77-word phrase "released under this license or ... compatible with the GPL v3" is supposed to mean. On the face of it, "released under this license or this license and [an open source license]" means exactly the same thing as "released under this license"; since you wrote 73 more words after that, you must have meant something different, but it's not clear what. Commented Nov 15, 2023 at 3:20
  • If you like the GPL v3, why not just use it? Which part specifically is hard to understand for you? It's a widely-known license so if you tell someone "it is GPL3 licensed" then most likely she will understand the gist of what that permission implies, without needing to pore over the GPL text in its entirety. As for special cases and niche issues, and why things in licenses are a certain way, that's one of the reasons for this SE, but you need to ask specifically about the specific thing in the license which is impenetrable for you, and then someone knowledgeable can shed light on it.
    – Brandin
    Commented Nov 15, 2023 at 7:01

1 Answer 1


Really, the comments above say everything that needs to be said, but I'll pull it together into a single answer.

Firstly, the GPL is complex in its writing because it's a legal document; it's meant to stand up in court, rather than be easily read by people, and it's done so successfully on numerous occasions. If it were easier to read, it would very likely be less effective in court, and that would be bad for everyone. The intent is simply expressed: if you use GPL code in your software, you must give to all recipients of your software full source code, a copy of the licence, and the same rights and obligations you were given.

Secondly, as Brandin says, everyone in the free software world already understands how the GPL works; when we see something's under GPL, we don't read the copy of the licence that comes with that software, we all just already know what we may, may not, must, and must not do with the software (that, by the way, is one reason why the GPL doesn't allow modified versions of itself to be distributed without a clear name-change). There are often questions about the fine detail, but the general principles of GPL compliance are well-understood.

Thirdly, even if you could write a shorter legally-robust copyleft licence, you shouldn't, for all the reasons that crayon licences are problematic. High amongst these is that very few people will use your software if they have to parse a new licence clause-by-clause to find out if they may do so. See, eg, this article, where a senior free-software lawyer in a large corporation says that if it takes him more than five seconds to work out whether a piece of software can be used by his company, he won't bother (full disclosure: I wrote that article, but I didn't give the talk on which it is based).

Stop worrying about the textual complexity of the GPL; it is much less off-putting to your potential users than anything shorter you could ever write would be.

  • "very few people will use your software if they have to parse a new licence clause-by-clause to find out if they may do so" – let's be realistic: quite a lot of people will use any code they find that seems to do what they want, without even thinking about looking at the license. (Or, they just scroll over the license without making much of an attempt to understand it in detail.) Not to say that this is a good thing. Commented Nov 16, 2023 at 10:32
  • @leftaroundabout you may well be right, but this site has very little to offer people who don't care about licences, so - at least here - it may be assumed that we're writing for the benefit of those who do.
    – MadHatter
    Commented Nov 16, 2023 at 10:43

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