10.0 Beta k/a Kodiak (a big bear)
10.0 Cheetah 24 March 2001 needed 64MB RAM but preferred 128 MB. Needed 800MB of disk space.
10.1 Puma 25 September 2001 Faster than Cheetah
10.2 Jaguar 23 August 2002 Introduced Universal Access, MPEG-4 video in QuickTime, Rendevous later named Bonjour
10.3 Panther 24 October 2003 Went from candy bar look to metal look. Introduced Exposé window management, FileVault, iChat, Safari. Cost $129
10.4 Tiger 29 April 2005 Introduced Spotlight, Dictionary, Automator, VoiceOver, QuickTime 7, Xcode 2.0. First OS to run on Intel processors.
10.5 Leopard 26 October 26 October 2007 Last version to work on Power PC. Introduced Boot Camp, Back to My Mac, Time Machine, iCal, Stacks, Quick Look, Spaces.
10.6 Snow Leopard 8 June 2009 Cost $29 Accepted 64 bit Apps. Introduced Mac App Store.
10.7 Lion 20 July 2011 Free. Introduced natural scrolling, trackpad gestures, Mission Control, LaunchPad, AirDrop, AutoSave. iDVD and iWeb dropped.
10.8 Mountain Lion 25 July 2012 Introduced Notes, Reminders, Messages replaced iChat, Notification Center. Integrated iCloud and Game Center. Let of the Big Cats.
10.9 Mavericks 22 October 2013 Redesigned the Dock, Contacts, Notes. Introduced iBooks, Maps, iCloud syncing. First to use California place names.
10.10 Yosemite 16 October 2014 Phone calls on iPhone could be answered on Mac. Personal Hotspot introduced.
10.11 El Capitan 30 September 2015 Introduced Split Screen. iPhoto and Aperture replaced by Photos
10.12 Sierra 20 September 2016 OS X renamed to macOS. Introduced Siri, Universal Clipboard, Apple File System (APFS) for SSDs, Unlock Mac with Apple Watch, Apple Pay in Safari.
10.13 High Sierra 25 September 2017 Improved Photos app. First OS on APFS. Metal 2G, High Efficiency Video Coding (HEVC).
10.14 Mojave 24 September 2018 Introduced Dark Mode, Voice Memos, Stocks, News, Home, Continuity Camera, Group FaceTime. Last OS to run 32 bit apps.
10.15 Catalina 7 October 2019 Could no longer run 32 bit apps. Last version of MacOS 10. Sidecar introduced. iTunes discontinued. Replaced by Music, Podcasts and TV. Introduced Mac Catalyst to bring iOS and iPadOS apps to Mac. Back to My Mac, Dashboard dropped.
11.0 Big Sur macOS 11 in beta. New look OS. Runs on Intel processors and on Apple Silicon processors soon to be released. Will run iOS apps. New Messages and Safari. Changes to Mac App Store., Music.