Looks all perfectly fine to me.
Most of us have our roots in the open source world, many (most?) of us learned coding because we were able to look at open source code, make changes to it, recompile and play with it.
We're trying to give back to the open source community and at the same time earn a living by asking the people who use Slint for proprietary apps (i.e. not giving back) to support us by purchasing a license.
All other so-called "free" licenses are just a way for corporations to co-opt the open source software community.
You say:
> The GPL is a good fit for open source users
As the thread tells you, it's clearly not for the many Apache/MIT licensed Rust projects that cannot use your GPL licensed code.
Again you say:
> With the GPL, we are happy to let open source users use the library for free. Commercial users still will be able to use the library because of the escape hatch of the dual license.
You make this differentiation between commercial and open source users while conveniently ignoring that the most permissively open source projects (Apache/MIT) are practically prevented from using your software.
At least with BSL, projects are honest about what they're doing. Don't play both sides.
An example of that is KHTML, the web engine: KHTML was licensed under LGPL, despite it was based on Qt in very deep ways (usage of core feature such as QString, QList, all over the place). Qt was GPL at the time. Even then, Apple was able to take KHTML, and remove the Qt dependency, in order to create WebKit which is fully LGPL.
One can totally make a "more permissive" product based on Slint. If someone wants to use the extra permissions that are not granted by the GPL, they still have the option to do so by purchasing a license, or using the free Slint license, or (worst case) porting away from Slint.
> Apache 2 software can therefore be included in GPLv3 projects, because the GPLv3 license accepts our software into GPLv3 works. However, GPLv3 software cannot be included in Apache projects. The licenses are incompatible in one direction only, and it is a result of ASF's licensing philosophy and the GPLv3 authors' interpretation of copyright law.
> This licensing incompatibility applies only when some Apache project software becomes a derivative work of some GPLv3 software, because then the Apache software would have to be distributed under GPLv3. This would be incompatible with ASF's requirement that all Apache software must be distributed under the Apache License 2.0.
> We avoid GPLv3 software because merely linking to it is considered by the GPLv3 authors to create a derivative work. We want to honor their license. Unless GPLv3 licensors relax this interpretation of their own license regarding linking, our licensing philosophies are fundamentally incompatible. This is an identical issue for both GPLv2 and GPLv3.
https://www.apache.org/licenses/GPL-compatibility
Am I missing something?
Personally, I'm not a big fan of licenses like GPL and BSL, but you do you. I just won't use your product.
If the former, this is laughably wrong and displays a complete misunderstanding of open source licensure. The GPL infects the entire project, that's its defining factor, and you cannot set the entire work's license as LGPL any more than you can set it as MIT.
If the latter, this is a fake distinction, and displays dishonesty about the risks. Regardless of what license I can distribute my code under later if I change it, in order to use a GPL-covered library I must license the version of my code that depends on it under the GPL. That version of the code will be GPL-licensed to anyone that has it, for eternity; I cannot retract it, regardless of what changes I make to my own copy.
Either way this is not a reassuring post. I am glad to know Slint is GPL so I can stay far away from it and recommend others do the same.
Then if someone wants to take that for proprietary software, they can do it too, like Apple. They don't even need to go as far as Apple and make a fork, they can use Slint's paid, or free as in beer (ambassador) license.