MacOS Sierra

macOS Sierra (10.12.x) is a version of macOS that was released on 20 September 2016. 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 non-SSE4 Intel CPUs (like the 65nm Core 2 Duo (Merom) and the 65nm Xeon (Clovertown).