To my understanding, that's fine for UXP applications themselves, but it would become a problem for flatpaks because they ship with the version of libstdc++ they are compiled against. And the libstdc++.so files are GPLv3, so if they are included in a flatpak, that would constitute a larger work, right?
GTK is under the LGPL, not the GPL. LGPL basically says that if you modify GTK itself you have to release your modifications to GTK, but you can do whatever you want in terms of licensing your own application that links against GTK.: https://gitlab.gnome.org/GNOME/gtk/-/blob/main/COPYING
Right, linking against GTK/glibc isn't where the issue comes in, if it were then we couldn't build against those libraries at all. The issue comes in when we include a bundled copy of glibc or GTK with the application, because then the flatpak is potentially considered a larger work that includes GTK.
There aren't any issues from a licensing perspective with these three specific components. I'm not sure what other GPL libraries we link against.
That is a good question, I am only aware of those three myself, but UXP is pretty huge and depends on a lot of stuff... it's definitely a reason to be careful when it comes to stuff like this. What's really noteworthy is that I think for the most part, the GPL-licensed stuff we rely on is the only real exception to our policy of not relying on system libs. I think on Windows, we actually do
ship the MSVC runtime libraries we use with the application because the license isn't viral and is permissive about letting you make sure the application has what it needs to run on computers that don't have MSVC installed, but this is all AFAIK and I am not really the expert on this.
"The Athenians, however, represent the unity of these opposites; in them, mind or spirit has emerged from the Theban subjectivity without losing itself in the Spartan objectivity of ethical life. With the Athenians, the rights of the State and of the individual found as perfect a union as was possible at all at the level of the Greek spirit." -- Hegel's philosophy of Mind