You're not wrong, but e.g. their license would not permit them to copy a bug fix from a similar wallet, which is under MIT, due to this clause.
That's again political bullshit that doesn't have to be there. I understand why it is done that way. You have put restrains on your software that doesn't allow anyone to change it or redistribute it, and as a punishment, you aren't allowed to use anything we release either. Politics.
Don't know if that's your definition of politics, sure.
I think it's good that corporations can't just take FOSS code that people developed for free or made available free of charge and go sell it to customers for big money.
Keep in mind the 2 definitions of
free: free as in freedom (free to use FOSS software, modify etc.) and free as in zero-cost (no licensing fees required).
Just like we value 'free' as in 'freedom' in Bitcoin in general; I believe that FOSS should really be the standard in this space.
What gives anyone the right to 'take software and redistribute it (maybe with some changes)' without 'giving back' as in: allowing others to also take this modified version of the software - either to improve the original codebase or to make another product out of it?
I didn't know that. So if I have a piece of software, it needs to be released under an MIT license for me to use any code from any other MIT licensed software?
Correct; that's pretty much the whole gist of the MIT license.
But wasn't ColdCard forked from Trezor's source code, which is also released under an MIT license?
I believe it just uses Trezor's crypto library, which is tried and tested, just like most other hardware wallet vendors. Because, well, it's tried and tested. But that requires the new product to be MIT, as well. Trezor just can't be bothered suing the Coinkite dev team, I guess, but they could easily do that, yes.
I do personally believe that Coinkite removed easily indentifiable references of using the Trezor library because of that, compared to Foundation Devices who are clear about it:
- trezor-firmware Contains a copy of the Trezor source code in order to use Trezor's crypto library. We will likely make this into a git submodule soon to make it even easier to keep the library up to date.
There are still some references in code comments, though...
https://github.com/Coldcard/firmware/search?q=trezor