Apple Computer introduced its first MacIntosh system in the
early 1980's.

The MacIntosh and Lisa computers featured an operating system
(OS) that was unsurpassed for ease of use by personal computer
users for many years.  The MAC-OS offered a superior
windowing environment.

Only when Commodore offered its Amiga operating system did the
personal computer market have a product comparable to the MAC
OS.

About a decade later Microsoft stumbled into the playing field
with its MESS Windows operating system.
