Information on the operating system, Macintosh.
Macintosh is a systems software developed by Apple who developed the first operating system to make use of a GUI which is now so popular.
The Mac operating system is used with Mac computers only so is a rather niche market in terms of operating systems. Mac computers are commonly used for graphics design so are very popular with users in the graphics design career.
The most up-to-date Mac operating system is Mac Mountain Lion.