A couple more come to mind:
- SwiftGTK: a full set of auto-generated Swift bindings for gtk-3 or gtk-4 that attempts to provide a more swifty wrapper around the GTK APIs (including the underlying layers such as Glib and Cairo-graphics,
- Tokamak: a cross-platform, open-source SwiftUI-compatible framework that works natively (with using GTK on Linux) as well as in the browser (using WASM),
- Swift Cross UI: another SwiftUI-like framework for creating cross-platform apps in Swift, using Gtk 4 as the backend