macOS Sierra (version 10.12) is the thirteenth major release of macOS (previously OS X), Apple Inc.'s desktop and server operating system for Macintosh computers. The successor to OS X El Capitan, it is the first version of the operating system issued under the June 2016 rebranding as macOS. Sierra is named after California's Sierra Nevada mountain range. Its major new features concern Continuity, iCloud, and windowing, as well as support for Apple Pay and Siri.
The first beta of macOS Sierra was released to developers shortly following the 2016 WWDC keynote on June 13, 2016. The first public-beta release followed on July 7, 2016. It was released to end users on September 20, 2016 as a free upgrade through the Mac App Store.
System requirements
macOS Sierra requires at least 2GB of RAM and 8GB of storage space and will run on:
- iMac: Late 2009 or newer
- MacBook: Late 2009 or newer
- MacBook Pro: Mid 2010 or newer
- MacBook Air: Late 2010 or newer
- Mac Mini: Mid 2010 or newer
- Mac Pro: Mid 2010 or newer
Sierra is the first version of macOS since OS X Mountain Lion, released in 2012, that does not run on all computers that the previous version supported. Developers have created workarounds to install macOS Sierra on some Mac computers that are no longer officially supported.
System features
The user can access the Siri intelligent assistant via the Dock, the menu bar or a keyboard shortcut and results are shown in a window in the upper-right corner. Siri can send messages, search the web, find files and adjust settings. Results can be dropped into other applications or pinned to Notification Center. For instance, pictures from search results can be dragged into a document.
iCloud Drive and Optimized Storage
iCloud Drive can upload the user's documents and desktop directories and sync them to other devices. The System Information application has a new section that gives the user detailed information about space usage per application or file and provides tools and suggestions for freeing up space. For instance, the user can let the system upload old files to iCloud Drive and remove their local copies, keeping them available on-demand in Finder. It can also remove old files from trash automatically. iTunes can delete watched, purchased films and TV programs from its library.
Auto Unlock and Universal Clipboard
Building upon Continuity, an "umbrella term [for] features that facilitate the communication between [Apple devices]" using Bluetooth and Wi-Fi, Sierra adds two features. With Auto Unlock, the user can unlock their user account by holding a paired Apple Watch close to the device. Time of flight is used to prevent relay attacks. Auto Unlock requires a Mac that was introduced in 2013 or later. The user can share the clipboard for cut, copy and paste between macOS Sierra and iOS 10 devices, including text and rich content, such as pictures or videos.
Tabs and Picture-in-Picture
Applications that support multiple windows can support multiple tabs within a single window, allowing the user to keep windows organized similarly to Safari. With Picture-in-Picture, videos can be played in a floating window that follows the user across the system.
Apple File System
Apple released a preview of a new file system, called Apple File System (APFS), to overcome the limitations of HFS Plus. It is intended for solid-state drives and flash memory and will adopt several features found in modern file systems, such as snapshots and cloning, as well as native support for features that Apple already provides in HFS Plus through supplementary software, such as file-system encryption and trim. The file system is currently experimental and a release is planned for 2017. Apple plans to document and publish the APFS volume format.
