Apple issues golden master of macOS High Sierra ahead of public launch Sept. 25

The company revealed earlier this week that High Sierra will publicly launch on Sept. 25, a few days after iOS 11, watchOS 4 and tvOS 11 debut on Sept. 19. Accordingly, the GM for High Sierra arrived a few days after the GMs for Apple's other platforms.

Typically a gold master issued to developers is identical to the version that eventually becomes the final release.

High Sierra brings the Apple File System to the Mac for the first time, while introducing support for a variety of other standards such as HEVC video, HEIF image encoding, and Apple's Metal 2 graphics platform. As usual Apple is also improving built-in apps like Safari, Mail, Notes, and Photos.

What will not ship with High Sierra is external GPU support, which allows Thunderbolt 3 PCI-E enclosures with a graphics card to connect to and accelerate graphics in High Sierra. That capability will come out of beta in spring of 2018.

Unveiled at Apple's Worldwide Developers Conference in June, High Sierra is seen as a refinement of its predecessor, Sierra. The new macOS 10.13 will include blocking of auto-play videos in Safari, new editing tools in Photos, and support for both virtual and augmented reality applications.