Mac OS X 10.0

Mac OS X 10.0 (code named Cheetah) is the first major release of macOS, Apple's desktop and server operating system. It was released on March 24, 2001, for a price of $129 after a public beta.

Mac OS X 10.0 box art

Developed by: Apple Computer

General availability: March 24, 2001 (version 10.0 build 4K78)

Last release: June 22, 2001 (version 10.0.4 build 4S10)

Preceded by: Mac OS 9

Succeeded by: Mac OS X 10.1 (codename Puma)

Kernel type: Hybrid (XNU)

Support status: Historical and no longer supported

Mac OS X was Apple's successor to the classic Mac OS. It was derived from NeXTSTEP and FreeBSD, and featured a new user interface called Aqua, as well as improved stability and security due to its new Unix foundations. It introduced the Quartz graphics rendering engine for hardware-accelerated animations. Many technologies were ported from the classic Mac OS, including Sherlock and the QuickTime framework. The core components of Mac OS X were open sourced as Darwin.

Boxed releases of Mac OS X 10.0 also included a copy of Mac OS 9.1, which can be installed alongside Mac OS X 10.0, through the means of dual booting (which meant that reboots are required for switching between the two OSes). This was important for compatibility reasons; while many Mac OS 9 applications could be run under Mac OS X in the Classic environment, some, such as applications that directly accessed hardware, could only run under Mac OS 9.

Six months after its release, Mac OS X 10.0 was succeeded by Mac OS X 10.1, code named Puma.

Features New and updated features Removed features
Architecture

Mac OS X is built on Darwin, a Unix-like operating system derived from FreeBSD. Darwin includes a new kernel, XNU, derived from Mach and BSD, as a replacement for the Mac OS nanokernel used in classic Mac OS.

Unlike Mac OS 9, Mac OS X has protected memory and preemptive multitasking. This means that if an application's memory becomes corrupted due to a bug, the application will crash without the entire system crashing and needing to be rebooted.

Mac OS X also had support for OpenGL, AppleScript, and the Carbon and Cocoa APIs.

Release History
Version Build Date Darwin version
10.0 4K78 March 24, 2001 1.3
10.0.1 4L13 April 14, 2001 1.3.1
10.0.2 4P12 May 1, 2001
10.0.3 4P13 May 9, 2001
10.0.4 4Q12 June 21, 2001
4R14 July 18, 2001
4S10 August 20, 2001
User Interface
Mac OS X 10.0 screenshot
A screenshot of Mac OS X 10.0 showcasing the new Aqua user interface