I was just confused about the term, and wanted to know what exactly it meant. It doesn't seem to be the (exactly) the opposite of copyright, but its license serves the opposite purpose(?).
Can someone please explain this (ELIA5 would be very appreciated)?
Thanks!
Cheers!
Cheers!
Top comments (6)
In general, a copyleft license means that anything that is built off of a copyleft software must also be copyleft. It also means making your code readily accessible when requested, which is a problem for closed source code (this is where your "opposite of copyright" research came in!).
It's super legal in what exactly "built off of" means -- some interpretations mean having an API that calls a copyleft service is enough while others say that building the code into your app is the only case. This is where having lawyers is useful. And the interpretations can be different per programming language based on the exact methods you use to ingest copyleft services.
A solid way of approaching it is that if your app cannot function without this piece, you are subject to copyleft. If your code is your product rather than a service, you shouldn't use copyleft licensed software. It doesn't mean you have to have your code on Github or indexable, but anyone should be able to email you and ask for your code and you provide it. I think you can charge a teeny fee for overhead but it can't be enough to deter someone from asking or you're in violation of the license.
TL;DR if you want to use copyleft software/services in closed source code, either don't or get a lawyer. If you want to in open source code, be mindful of what license you publish under or get a lawyer.
I was thinking not just for code, but just in general. But thanks, this really helps further my understanding.
Hmmm since a lot of the language around copyleft is around building solutions with copyleft licensed work, I can't really think of a non-code answer.
I got a lot of what I know off of data science forums since there's a whole lot of back and forth on the internet on whether or not a data analysis using R (which is copyleft) must also be publicly accessible. And since data analysis isn't much use other than on its own, that would kill any commercialization of the data work. This is probably why Python got so popular, to be honest.
For me, I always understood it as if your code is copyleft it must follow below:
My impression is that copyleft isn't the opposite in terms of law, but in terms of intended side effects.
Copyright, at least from a casual observer, was always intended to control how your work got distributed (if it could at all) and preventing it from unauthorised distribution.
Whereas Copyleft seems to go out of its way to enforce that you absolutely must share the work and make sure that if you make a derivative of the work, then that derivative must also be sharable in the same way.
I don't think it's quite so simple as that though. That above description does a good job of describing e.g. GNU GPL license, but BSD gives permission to copy, modify, and distribute the current code, but it doesn't apply to derivative works. Given how quite a lot of modern proprietary systems are based on BSD (e.g. macOS, Playstation's OS, Nintendo Switch, etc), this means that any BSD core can be tweaked, but the derivative works can be and often are incredibly proprietary.
I think in general, Copyleft and its licenses are about letting other people be the owners of your code, and there are multiple licenses to deal with that level of control. The GNU GPL can be seen as the "extreme" version where everything must be shared, and then there are 4-Clause BSD License all the way down to 0-Clause BSD License.
But I should add that I'm not a lawyer, and I could be very wrong on any part or all of what I said.
Thank you, this helped clear some confusion I had.
Copyright is the right to make copies of something.
The GNU people wanted to ensure that everyone could make copies of everything.
So they give you the right to copy things, but only if you in turn give others the right to copy your copy of the thing.