- GtkRoot — Interface for root widgets
- GtkNative — Interface for widgets having surfaces
- GtkWindow — Toplevel which can contain other widgets
- GtkDialog — Create popup windows
- GtkMessageDialog — A convenient message window
- GtkAboutDialog — Display information about an application
- GtkAssistant — A widget used to guide users through multi-step operations
- GtkWindowGroup — Limit the effect of grabs
- GtkNativeDialog — Integrate with native dialogs