It looks like they ported Qt to SerenityOS. I saw a package called "qt6-serenity". Perhaps they use the SerenityOS GUI libraries underneath. Does anyone know?
Ladybird is a browser based on SerenityOS technologies that uses Qt as the GUI framework. In SerenityOS, they have their own browser using the same underlying technologies, but a different in-house GUI framework.
WebKit and Blink are similar in how they have their different counterparts like QtWebEngine or WebKitGTK. The equivalent to WebKit and Blink in SerenityOS is called LibWeb.
Hmm, I was actually asking if SerenityOS released a "fork" of Qt that re-implements class QPaint to use their native GUI API. I assume yes. QPaint is turtles all the way down to paint pixels on any platform -- MacOS, Win32, X Windows, Wayland, Android, iOS, embedded (auto), etc.