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