Intuition is the native windowing system and user interface (UI) engine of AmigaOS. It was developed almost entirely by RJ Mical. Intuition should not be confused with Workbench, the AmigaOS spatial file manager, which relies on Intuition for handling windows and input events.
Intuition is the internal widget and graphics system. It is not implemented primarily as an application-managed graphics library (as most systems, following Xerox' design, have done), but rather as a separate task that maintains the state of all the standard UI elements independently from the application. This makes it responsive because UI gadgets are live even when the application is busy. The Intuition task is driven by user events through the mouse, keyboard, and other input devices. It also arbitrates collisions of the mouse pointer and icons and control of "animated icons". Like most GUIs of the day, Amiga's Intuition followed Xerox's lead anteceding solutions, but pragmatically, a command line interface was also included and it extended the functionality of the platform. Later releases added more improvements, like support for high-color Workbench screens and 3D aspect. Replacement desktop file managers were also made available, such as Directory Opus Magellan, or Scalos interface. (Full article...)