One line of code brings one fully to life. Most objects are similarly high level - windows, dialog boxes, menus, files, resources, etc. Floating windows float automatically, and disappear when the app is put into the background. Edit fields in dialogs allow you to filter keystrokes as they are typed. Windows close, zoom and update without any intervention on your part.
Printing just works.
The menubar is automatically created, including all hierarchical submenus. Menu context is quickly and easily established as different windows and views are activated. Undo just works. Scrolling just works. Preferences are put in the right prefs folder automatically.