Mac OS X Jaguar (version 10.2) is the third major release of macOS, Apple's desktop and server operating system.

Mac OS X Jaguar Server 10.2.2 added journaling to HFS Plus, the native Macintosh file system, to add increased reliability and data recovery features.

The technology allotted the task of drawing the 3D surface of windows to the video card, rather than to the CPU, to increase interface responsiveness and performance.

The Happy Mac startup icon that was introduced with the original Macintosh was replaced with a grey Apple logo.

Teachers who wanted to get a copy had to fill out a form and a packet containing Mac OS X installation discs and manuals was then shipped to the school where they taught.