Apache Karaf with OSGi works pretty nice using annotation based dependency injection with the declarative services, removing the need to mess with those hopefully archaic XML blueprints. Too bad it's not as trendy as spring and the developers so many of the tutorials can be a bit dated and hard to find. Karaf also supports many other frameworks and programming models as well and there's even Red Hat supported... Source: about 3 years ago

There are a lot of third-party Linux apps built with GTK4/Libadwaita. If you just to to https://flathub.org and click on random apps a lot of them will use GTK. - Source: Hacker News / 2 months ago

I would recommend taking a look at Flatpak. Source: 6 months ago

Flathub flatpak format apps/games for linux desktop, does not require any specific linux distribution just that flatpak is present on the system. Source: 8 months ago

Which X clients are these? You didn't name any so let's just look at some of the popular and recent flathub apps: https://flathub.org/ I see a lot of games, chat apps, text editors, photo apps, office apps. These all will work fine in XWayland and XQuartz. But also, it's relatively easy to get them running on Wayland natively. - Source: Hacker News / 8 months ago

If you're worried about the potential of breaking things, I'd pick the Fedora Kinoite distro. Up to date gaming support, stable and extremely difficult to break. Install apps from Flathub using the built-in Discover software store and go nuts. Source: 8 months ago