But you can create a new version with changes and a different license. The new license only applies to the new changes, but if users use the software as a whole, users must comply with the new license (as well as the MIT license, which continues to apply to the unchanged parts).
As an oversimplification, if you combine 2 components with 2 different licenses into 1 work, the recipients have to comply with both licenses. MIT has few requirements and I believe the AGPL includes all of them. So while technically the MIT license still applies to the old code that did not change, from the point of view of a recipient of the combination, the results looks like a relicense.
>MIT license still applies to the old code that did not change, from the point of view of a recipient of the combination, the results looks like a relicense.
That's again not true, you cannot delete the MIT license from that file, it's not important if you changed it, the original license is still there plus your license that don't contradicts the MIT license like "our license allows to delete all prior licenses" yes your added code is exclusively under your license but the whole file is MIT+ that was partially confirmed with the BSD and AT&T lawsuit (when AT&T took BSD code deleted the license and lost because AT&T "stole" more code as Berkley hmmm f're'e-licensed ;)
That sounds very arbitrary but if that's the case, instead of changing the MIT-licensed file you can just create a new one and put the changed code there. Eventually the MIT one will just be empty, or all of its functions unused and it can be deleted.
>instead of changing the MIT-licensed file you can just create a new one and put the changed code there.
Yes do that...even in the same file and put your License above or under the MIT one's...no problem (sub-license).
I don't get it, what are you trying to say? MIT gives you the right to do nearly everything. Just don't take the copyright and license from the work and the people who made it. It's not viral.
I'm not a lawyer, I just read the copyright lawyers who post here, but I don't think this is all that complicated? Once a literal, specific, concrete file is released MIT, you can't "take it back". That specific file will always be MIT. But you can, on a forward-moving basis, license all your own changes to that file however you'd like. The changes (and the changed versions of the file) have, absent some binding contract that says otherwise, their own copyright status.
This is why there is, for instance, OpenSSH: it's the version of SSH that started when the SSH company decided to use a restrictive license on a forward-moving basis. The community just forked at the last permissive version and took over development themselves.
>That specific file will always be MIT. But you can, on a forward-moving basis, license all your own changes to that file however you'd like.
Exactly, that file is then MIT+YourLicense but one can never take the MIT license away (except the copyright holder).
Take away a (not owned) Copyright would be called stealing.
Even the BEER-WARE LICENSE has this sentence:
>As long as you retain this notice you can do whatever you want with this stuff. If we meet some day, and you think this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
I think the original author (or their heirs) can take away that MIT license during a special “copyright termination” window 35 years after granting it at least in the USA.
This is the whole point of permissive licenses - the restrictions on what you do with it are minimal.
It is common for permissively licensed software to be redistributed under proprietary licenses too.