Mac OS X Lion
Mac OS X 10.7 "Lion" is a version of Mac OS X. A preview of Lion was publicly unveiled at Apple's "Back to the Mac" event on October 20, 2010. It brought several developments made in Apple's iOS, such as an easily-navigable display of installed applications, to the Mac, and includes support for the Mac App Store, as introduced in Mac OS X Snow Leopard version 10.6.6. On February 24, 2011, the first Developer Preview of Lion (11A390) was released to subscribers of Apple's developers program. The latest preview (build 11A459e) was released on May 13, 2011. It was scheduled to release on Summer 2011, and Lion was unveiled by Steve Jobs on June 6th at the WWDC 2011. This was the last version of the Mac OS developed and released before Steve Jobs died.
Lion is the first version of Apple's OS to be referred to as "OS X", dropping the "Mac" from the name of the operating system. This would foreshadow Apple's later decision to drop the OS X moniker altogether with Mac OS 10.12 and refer to the system as macOS. It adds Natural Scrolling (or simply kinetic scrolling), a refined Aqua UI with a new login screen and iOS-like scrollbars that autohide, a refined Finder, AutoSave in supported applications, fullscreen support, Launchpad, Mission Control, a new iteration of XCode, the new OS X Utilities frontend, iCloud integration, an on-board Restore partition, and more.
It drops PowerPC application support (Rosetta), and is the first release of the Mac OS that was released and distributed digitally through the Mac App Store rather than on optical media (or floppies) for $29.99. However, it is possible to buy an alternate OS X Lion USB Recovery Key for $69, or already have a recovery disk that ships with Mac models built around that time to restore Lion without needing to download it from the Mac App Store. Since it was distributed around an Apple ID, it was legally possible to install Lion using the Store on 5 clients, rather than the single license previous versions had offered. A 64-bit processor, such as an Intel Core 2 Duo or newer and 2 GB of RAM are required.