MacOS Sierra

macOS Sierra, or macOS 10.12, is the thirteenth major release of macOS that was released on 20 September 2016. It was announced on 13 June 2016 at WWDC. It is the first version of Mac OS X to use the "macOS" branding for marketing materials, matching the rest of Apple's OS names (iOS, watchOS, tvOS, etc). It is the first version of macOS to drop support for Intel processors without SSE4.1.