History of Mac OS X

Source

This article is part of the Mac OS X series.

New features

History

Transition to Intel processors

Architecture

Technologies

List of applications

Components

Mac OS X is the newest of Apple Inc.'s Mac OS line of operating systems. Although it is officially designated as simply "version 10" of the Mac OS, "version 9" had a completely different codebase, file system, design, and hardware support. Mac OS had been Apple's primary operating system since 1984, and the family was backward compatible, so Mac OS X supported an emulated version 9 until version 10.5.

Unlike its predecessor, Mac OS X is a Unix-like operating system built on technology that had been developed at NeXT through the second half of the 1980s and up until Apple purchased the company in early 1997. It was first released in 1999 as Mac OS X Server 1.0, with a desktop-oriented version (Mac OS X v10.0) following in March 2001. Since then, six more distinct "client" and "server" editions of Mac OS X have been released, the most recent being Mac OS X v10.6, which was first made available on August 28, 2009. Releases of Mac OS X are named after big cats; the current version of Mac OS X is nicknamed "Snow Leopard".

Diagram of the relationships between Unix systems including the ancestors of Mac OS X