No it doesn't. If you're the sole copyright holder of the code (e.g. it's a project you did by yourself), you can do what you want with it, including switching to a proprietary license. You can't retroactively un-GPL any copies that other people already have, of course, and it probably would look bad to take away older GPL versions from your GitHub page or wherever they're hosted, but you absolutely can make all new versions proprietary if you want.
> You can't retroactively un-GPL any copies that other people already have
That's what I meant when I said that you can't revoke the GPL. Of course with new versions you have more freedom, but what was relased under the GPL remains available under the GPL.
> but what was relased under the GPL remains available under the GPL.
Not necessarily. The copyright holder only has to provide source to those who got it from them under a GPL license. Others may not be able to get a copy, as those who can ask you for it aren’t obliged to give it to them on request (https://www.gnu.org/licenses/gpl-faq.html#CanIDemandACopy)
There also is the issue as to what happens when a license holder dies or is dissolved. I think that’s a gray area. Let’s say company Foo releases a product with a GPL license and later goes bankrupt. If Bar buys the source code from the bankrupt company, I don’t see how they would have to release it under the GPL, or should legally be obliged have to give the source code to those who got a license from Foo, and Foo can’t provide it anymore, as it doesn’t exist.
Similarly, if you only give (or sell) your GPL-licensed software to an individual who later dies, does their estate inherit the right to ask you for the source code?
>> > but what was relased under the GPL remains available under the GPL.
perhaps, in line with what you are saying, t would be better to express this as;
"but what was obtained under the GPL remains obtained under the GPL."
In other words, at a moment in time, a user can request the source of the (GPL) product they are using. They have rights and obligations for that code as it exists then.
It does not give them a right to any later versions of that code. And it does not allow the author to retroactively "deny" the rights they have.
One of the rights they have is to publish that code. (more accurately they can publish something based on the code, and hence by extension pass on the code to more users.)
Nothing says the original author as to keep the GPL version in any kind of public place. And the original author (assuming he has 100% copyright) can of course build on that code himself, and release the new code (or indeed the same code) under a different license.
>The copyright holder only has to provide source to those who got it from them under a GPL license. Others may not be able to get a copy, as those who can ask you for it aren’t obliged to give it to them on request
That's true, but if the software is at all widely distributed, then there's lots of people who have a copy theoretically, and any one of them could distribute their copy. So, in practice, once the cat is out of the bag, it's very hard to get it back in. But if the copyright holder changes the license (even on older versions) and no one still has a copy of those older GPL-licensed versions (or isn't willing to send a copy), then sure, in effect the copyright holder could retroactively un-GPL the whole thing.
You provided some interesting points. But now this discussion is going off-rails, as the potential issues you pointed at don't seem relevant in the case discussed here.
Then that code is under the new license. Yes, you can still use the first version under GPL license. But nothing stops me from granting a new license in addition to GPL. Remember GPL is only a license. It doesnt take away the underlying ownership to the IP. It becomes more problematic of course if the first version isnt 100% written by me. Then I would need any contributors permissions too.