- GApplication — Core application class
- GApplicationCommandLine — A command-line invocation of an application
- GActionGroup — A group of actions
- GActionMap — Interface for action containers
- GSimpleActionGroup — A simple GActionGroup implementation
- GAction — An action interface
- GSimpleAction — A simple GAction implementation
- GPropertyAction — A GAction reflecting a GObject property
- GRemoteActionGroup — A GActionGroup that interacts with other processes
- GActionGroup exporter — Export GActionGroups on D-Bus
- GDBusActionGroup — A D-Bus GActionGroup implementation
- GMenuModel — An abstract class representing the contents of a menu
- GMenu — A simple implementation of GMenuModel
- GMenuModel exporter — Export GMenuModels on D-Bus
- GDBusMenuModel — A D-Bus GMenuModel implementation
- GNotification — User Notifications (pop up messages)