Licensing Clarification: GPLv3-Slint + Binary Releases

[Evrey]

Hello, this is about that table in one of your recent blog posts:

… where it says, if i pick Slint under GPLv3, i can license my source code under GPLv3-compatible (e.g. AGPL, or EUPL). So far so lovely. However, under »binary releases« it says »Must be GPLv3«, exactly. Any good reason for not also saying »GPLv3-compatible«? Because i would greatly prefer to also license the binaries under EUPL/AGPL, which are compatible, but also more restrictive than the GPLv3.

So, clarification requested: Must binaries also be GPLv3, if so why? Or is the real goal to ensure binaries are released under a license at least as restrictive as the GPLv3?

And yes, effectively this is all about the extra SaaS clauses.

[ogoffart]

I think this is just a shortcut. GPL-compatible licenses like MIT or Apache are more permissive than the GPL. But since the binary includes Slint, it must follow the GPL rules. So, when we say "Must be GPLv3," we mean the binary can't be MIT, because MIT would let someone patch the binary and add features without releasing the source code, which breaks Slint's GPL.

That said, licensing the binary under the AGPL is fine because Section 6 of the GPLv3 allows it.

I don’t know enough about the EUPL, but I think it’s okay too since the EUPL has rules that say it’s compatible with the GPL.

[Evrey]

Makes perfect sense, thanks!