The way it works is:

A company adopts some software with a free but not copyleft license. Adopts means they declare "this is good, we will use it".

Developers help develop the software (free of charge) and the company says thank you very much for the free labour.

Company puts that software into everything it does, and pushes it into the infrastructure of everything it does.

Some machines run that software because an individual developer put it there, other machines run that software because a company put it there, some times by exerting some sort of power for it to end up there (for example, economic incentives to vendors, like android).

A some point the company says "you know what, we like this software so much that we're going to fork it, but the fork isn't going to be free or open source. It's going to be just ours, and we're not going to share the improvements we made"

But now that software is already running in a lot of machines.

Then the company says "we're going to tweak the software a bit, so that it's no longer inter-operable with the free version. You have to install our proprietary version, or you're locked out" (out of whatever we're discussing hypothetically. Could be a network, a standard, a protocol, etc).

Developers go "shit, I guess we need to run the proprietary version now. we lost control of it."

This is what happened e.g. with chrome. There's chromium, anyone can build it. But that's not chrome. And chrome is what everybody uses because google has lock-in power. Then google says "oh I'm going to disallow you running the extensions you like, so we can show you more ads". Then they make tweaks to chrome so that websites only get rendered well if they use certain APIs, so now competitors to Chrome are forced to implement those APIs, but those aren't public.

And all of this was initially build by free labour, which google took, by people who thought they were contributing to some commons in a sense.

Copyleft licenses protect against this. Part of the license says: if you use these licenses, and you make changes to the software, you have to share the changes as well, you can't keep them for yourself".

> This is what happened e.g. with chrome. There's chromium, anyone can build it. But that's not chrome. And chrome is what everybody uses because google has lock-in power.

Because Google has their attention. You can use chromium, but most people don't and pick the first thing they see. Also, Chrome is a much better name, err, not better but easier to say.

> Then google says "oh I'm going to disallow you running the extensions you like, so we can show you more ads". Then they make tweaks to chrome so that websites only get rendered well if they use certain APIs, so now competitors to Chrome are forced to implement those APIs, but those aren't public.

You and I have a different definition of "forced". But, are you speculating this might happen, or do you have an example of it happening?

> And all of this was initially build by free labour, which google took, by people who thought they were contributing to some commons in a sense.

Do you have an example of a site that works better in chrome, than it does in chromium? I'll even take an example of a site that works worse in the version of chromium before manifest v2 was disabled, compared to whatever version of chrome you choose?

> Copyleft licenses protect against this. Part of the license says: if you use these licenses, and you make changes to the software, you have to share the changes as well, you can't keep them for yourself".

Is chromium not still foss? Other than branding, what APIs or features are missing from the FOSS version? You mentioned manifest v3, but I'm using firefox because of it, so I don't find that argument too compelling. I don't think FOSS is worse, I think google is making a bad bet.

Large parts of Chrome are actually GPL AFAIK, which is one reason both Apple and Google made it open source in the first place.

> chrome is what everybody uses because google has lock-in power.

Incorrect. At least on Windows, Chrome is not the default browser, it is the browser that most users explicitly choose to install, despite Microsoft's many suggestions to the contrary.

This is what most pro-antitrust arguments miss. Even when consumers have to go out of their way to pick Google, they still do. To me, this indicates that Google is what people actually want, but that's an inconvenient fact which doesn't fit the prevailing political narrative.

> so that websites only get rendered well if they use certain APIs, so now competitors to Chrome are forced to implement those APIs, but those aren't public.

What is a Chrome API that web developers could possibly implement but that "isn't public?" What would that even mean in this context?

> google says "oh I'm going to disallow you running the extensions you like, so we can show you more ads".

And that could have happened just as well if Chrome was 100% open source and GPL.

Even if you accept the claim that Manifest V3's primary purpose was not increasing user security at face value (and that's a tenuous claim at best), it was perfectly possible for all third-party browsers (notably including Edge, which has 0 dependency on Google's money) to fork Chromium in a way that kept old extensions working. However, open source does not mean that features will magically appear in your software. If Google is the primary maintainer and Google wishes to remove some feature, maintaining that feature in your fork requires upkeep, upkeep that most Chromium forkers were apparently unwilling to provide. This has nothing to do with whether Chrome is open source or not.

>> A some point the company says "you know what, we like this software so much that we're going to fork it, but the fork isn't going to be free or open source. It's going to be just ours, and we're not going to share the improvements we made"

Right. So at that point all those contributing developers are free to fork, and maintain the fork. You have just as much control as you always did.

And of course being MIT or GPL doesn't make a difference, the company is permitted to change the license either way. [1]

So here's the thing, folk are free to use the company product or not. Folk are free to fork or not.

In practice of course the company version tends to win because products need revenue to survive. And OSS has little to zero revenue. (The big revenue comes from, you know, companies who typically sell commercial software.)

Even with the outcome you hypothesize (and clearly that is a common outcome) OSS is still ahead because they have the code up to the fork. And yes, they may have contributed to earn this fork.

But projects are free to change license. That's just built into how licenses work. Assuming that something will be GPL or MIT or whatever [2] forever is on you, not them.

[1] I'm assuming CLA us in play because without that your explanation won't work.

[2] yes, I think GPL sends a signal of intention more than MIT, but it's just a social signal, it doesn't mean it can't change. Conversely making it GPL makes it harder for other developers to adopt in the first place since most are working in non-GPL environments.