<operating system> The graphical user interface used by Apple Computer's Macintosh family of personal computers, based on graphical representations of familiar office objects (sheets of paper, files, wastepaper bin, etc.) positioned on a two-dimensional "desktop" workspace.
Programs and data files are represented on screen by small pictures (icons). An object is selected by moving a mouse over the real desktop which correspondingly moves the pointer on screen. When the pointer is over an icon on screen, the icon is selected by pressing the button on the mouse.
A hierarchical file system is provided that lets a user "drag" a document (a file) icon into and out of a folder (directory) icon. Folders can also contain other folders and so on. To delete a document, its icon is dragged into a trash can icon. For people that are not computer enthusiasts, managing files on the Macintosh is easier than using the MS-DOS or Unix command-line interpreter.
The Macintosh always displays a row of menu titles at the top of the screen. When a mouse button is pressed over a title, a pull-down menu appears below it. With the mouse button held down, the option within the menu is selected by pointing to it and then releasing the button.
Unlike the IBM PC, which, prior to Microsoft Windows had no standard graphical user interface, Macintosh developers almost always conform to the Macintosh interface. As a result, users are comfortable with the interface of a new program from the start even if it takes a while to learn all the rest of it. They know there will be a row of menu options at the top of the screen, and basic tasks are always performed in the same way. Apple also keeps technical jargon down to a minimum.
Although the Macintosh user interface provides consistency; it does not make up for an application program that is not designed well. Not only must the application's menus be clear and understandable, but the locations on screen that a user points to must be considered. Since the mouse is the major selecting method on a Macintosh, mouse movement should be kept to a minimum. In addition, for experienced typists, the mouse is a cumbersome substitute for well-designed keyboard commands, especially for intensive text editing.
Urban legned has it that the Mac user interface was copied from Xerox's Palo Alto Research Center. Although it is true that Xerox's smalltalk had a GUI and Xerox introduced some GUI concepts commercially on the Xerox Star computer in 1981, and that Steve Jobs and members of the Mac and Lisa project teams visited PARC, Jef Raskin, who created the Mac project, points out that many GUI concepts which are now considered fundamental, such as dragging objects and pull-down menus with the mouse, were actually invented at Apple.
Pull-down menus have become common on IBM, Commodore and Amiga computers. Microsoft Windows and OS/2 Presentation Manager, Digital Research's GEM, Hewlett-Packard's New Wave, the X Window System, RISC OS and many other programs and operating environments also incorporate some or all of the desktop/mouse/icon features.
Apple Computer have tried to prevent other companies from using some GUI concepts by taking legal action against them. It is because of such restrictive practises that organisations such as the Free Software Foundation previously refused to support ports of their software to Apple machines, though this ban has now been lifted. [Why? When?]