Mac OS X Tiger (version 10.4) is the fifth release of macOS, shipped on April 29, 2005, and the longest-serving of the classic era — thirty months as the current release, spanning the platform's most consequential transition: with 10.4.4 in January 2006, Tiger booted the first Intel Macs, carrying Rosetta's PowerPC translation and the Universal Binary format through Apple's processor migration.

Its features eclipsed even that: Spotlight brought instant system-wide search a decade before rivals matched it, and Dashboard's widget layer introduced the mini-app concept the industry kept reinventing.

Spotlight; Dashboard widgets; Automator workflow automation; Smart Folders and Mailboxes; VoiceOver's screen-reader debut; QuickTime 7 with H.264; Safari RSS; and — under the hood — Core Image, Core Data, and the 64-bit foundations developers built the next decade on. Tiger also shipped on the Apple TV's first generation and demoed the iPhone's software base.

Tiger is remembered as the classic-era peak: the release Windows Vista was measured against (unfavorably) and the one that executed the Intel transition so smoothly it became Apple's migration playbook — reused for Apple silicon fifteen years later. Spotlight's instant-index search became a universal OS expectation.