These classes provide everything you need for a typical modern main application window, like the main window itself, menu and tool bars, a statusbar, etc.
| QAbstractEventDispatcher | Manages Qt's event queue, excluding GUI-related events | 
| QAction | Abstract user interface action that can be inserted into widgets | 
| QActionGroup | Groups actions together | 
| QApplication | Manages the GUI application's control flow and main settings | 
| QCoreApplication | Event loop for console Qt applications | 
| QDockWidget | Widget that can be docked inside a QMainWindow or floated as a top-level window on the desktop | 
| QMainWindow | Main application window | 
| QMenu | Menu widget for use in menu bars, context menus, and other popup menus | 
| QMenuBar | Horizontal menu bar | 
| QSessionManager | Access to the session manager | 
| QSizeGrip | Corner-grip for resizing a top-level window | 
| QStatusBar | Horizontal bar suitable for presenting status information | 
| QToolBar | Movable panel that contains a set of controls | 
| QWorkspace | Workspace window that can be used in an MDI application |