macOS Sierra (version 10.12) is the thirteenth major release of macOS, Apple Inc.'s desktop and server operating system for Macintosh computers. It is the successor to OS X v10.11 El Capitan, and was announced on June 13, 2016 at WWDC 2016. It was released to developers shortly following the WWDC keynote. In order to match the naming scheme used for Apple's other operating systems (watchOS, tvOS, iOS), it is the first Mac software branded as macOS, reminiscent of the old naming scheme used since Mac OS 7.6.