After its hardware event earlier this week, Apple released GM seeds for iOS 11, watchOS 4, and tvOS 11. Notably missing was macOS 10.13 High Sierra was notably missing, and we learned that the OS will launch a week later than the others.
Today though, the firm is offering the macOS High Sierra GM seed to both developers and public beta testers. This should be the final build that the public will get on September 25.
One of the key features in High Sierra will be the Apple File System (APFS). There are still some issues though; HDD-only Macs and iMacs with 3TB Fusion drives and BootCamp won't be supported for conversion to the new file system. Also, some third-party apps won't recognize the new format, but that's up to the developers to fix.
The new version of the OS also supports HEVC and HEIF media, as iOS 11 adds the ability to capture photos and videos in those formats. Naturally, you'll need to upgrade your Mac to High Sierra in order to view those photos and videos.
If you're already testing out the High Sierra beta, you can upgrade to the GM seed through the Mac App Store.