Since the explosion in generative AI, there has been a rash of “decompilations” of video games and various other software (such as this example from earlier today disputed – see below) that have been published to Github and advertised as “Open Source.” That claim is a lie.
The phrase “Open Source” has a specific meaning (and similarly for “Free Software,” by the way1), and it isn’t merely that the source code is there for you to look at. It means that the copyright holder is explicitly giving you permission to read that source code, modify it, redistribute it, etc. Without that element of permission, the code cannot be “Open Source” even if you can physically read it. At best, it might be “Fair Use” depending on the circumstances, but it’s most likely just a fancy means of copyright infringement.
Remember, copyright is a legal construct, not a technical one. It depends much more on the intent of the human doing the copying than it does on the technical details of what they actually did. If the thing they have is obviously intended to be a copy of something else, it is a Derivative Work no matter what technical means were used to create it. That means the original copyright still attaches to it and the person who made the copy doesn’t get to choose a new license for it, “Open Source” or otherwise.
Why YSK:
You don’t have to like the way copyright law works – I sure don’t! – but you do have to understand it because there’s a lot of misinformation going around right now with people claiming things are “Open Source” when they aren’t and a lot of people are going to get in trouble for it. It also dilutes the public understanding of what actual legitimate Open Source software is, which is a problem in and of itself.
Conflating real Open Source software with proprietary software that’s been ‘pirated with extra steps’ is harmful both for developers of the former, who have their reputations damaged by association, and for users/sharers of the latter, who might be misled into not taking the same precautions that they would if they understood that they were dealing with warez. Just because you might think Big Tech can get away with laundering copyright through LLMs – and even that remains to be seen – doesn’t mean the little guys can.
TL;DR: Proprietary software cannot become Open Source software by any means except (a) the express consent of the copyright holder or (b) the copyright expiring and the work becoming Public Domain. Whatever technological end-run you think you have around this legal fact, no you don’t.
EDIT: dispute over example
In giving that example I was relying on the claim in the linked thread, which comes from this guy on BlueSky. Seems like a lot of people think he’s wrong, so maybe that’s not a good example after all.
However, there are also things like this, and those are examples I feel very confident in citing because (a) they explicitly call them “decompliations,” (b) at least one of them has a LICENSE file that says it’s MIT, and (c) there’s zero chance Nintendo or Rare or anyone else legitimately gave them permission for it.
footnote
1 “Free Software” has essentially the same denotation as “Open Source” – close enough that every “Free Software” license is also “Open Source” and vice-versa – but a different connotation. The term “Free Software” tends to get used by people who wish to emphasize the rights of the end-user, while the term “Open Source” tends to get used by people who wish to emphasize that the software is available to be modified.
Free- and open source is not the same! Open source doesn’t necessarily grant you the right to modify and redistribute
You’re right, but in reality it usually doesn’t matter. All common licenses (GPL, LGPL, MIT, BSD, Apache, MPL) fit both definitions: free software as defined by FSF, and open-source as defined by OSI.
It’s only really niche licenses where it differs - for example NASA’s Open Source Agreement is open-source (OSI approved) but not free (not FSF approved) because of this clause:
This is what the FSF say about it:
Note that “free” refers to freedom, not price. Both definitions allow you to charge money for the software. However, you can’t restrict the user’s freedoms, so someone that buys the software could give it to someone else for free, and you wouldn’t be able to stop that while still remaining FOSS.
No, read the definition I cited. “Open Source” is a term of art defined by the Open Source Initiative, and definitely does grant you the right to modify and redistribute.
I thought they were all separate. Distribution and modification are defined by the license type and open source means you can see the code.
All three are defined by the license.
Some software is “source-available”, meaning you can see the code but it’s not open-source. Microsoft uses to do this a lot with the .NET Framework (they called it “shared source”), before they created a new version that was open-source from the beginning.
One of the issues with this type of code is that it often taints you. With the old .NET shared source for example, you weren’t allowed to redistribute the code or use it for other purposes. if you ever looked at that source code, you weren’t allowed to contribute to competing open-source projects like Mono, since they had no way to guarantee that the code you were contributing wasn’t influenced by what you saw in the shared source, or that you didn’t just copy and paste it from Microsoft’s code.
There’s some popular self-hosted projects that are source-available rather than open-source, like n8n and Sentry.
These days it’s more common for software to be “open core”, meaning the core functionality is open-source, but extra stuff around it is only source-visible with a proprietary license, usually requiring a paid subscription to be allowed to use it.
Nah, that’s just what corporate bad actors like Microsoft want you to think. Lots of entities have an ulterior motive to dilute the term “Open Source” to make their proprietary stuff seem more open than it is, but that must be resisted.
See also:
https://en.wikipedia.org/wiki/Source-available_software#Distinction_from_free_and_open-source_software
https://en.wikipedia.org/wiki/Openwashing
What you have in mind is “source available”.