MacOS High Sierra (10.13)

MacOS 10.13, which quietly switched the Mac's underlying filesystem to APFS — still a realistic target for genuinely old (2009-2010) Macs too old for anything newer.

legacyvery-old-hardwarestill-downloadableDownload / Upgrade ↗Official page ↗Lifecycle / Support docs ↗

Platform

MacOS

Released

September 2017

Support ends

Still supported

System requirements

MacBook (2010 or later), MacBook Air (2010 or later), MacBook Pro (2010 or later), Mac mini (2010 or later), iMac (2009 or later), Mac Pro (2010 or later).

High Sierra's headline change happened almost invisibly to most users: it migrated Macs from the decades-old HFS+ filesystem to APFS, Apple's modern copy-on-write filesystem, in the background during upgrade. It remains the newest MacOS many 2009-2010 Macs can run at all. Apple has hidden its Mac App Store listing from search, but the direct link to that same listing still works -- a real, if less discoverable, official download path.

Release dates, support windows, and system requirements come from Microsoft's and Apple's own published lifecycle pages (linked above) — always confirm there before relying on this for a production/enterprise deployment decision, since support policies occasionally change.