Apple seeded macOS High Sierra 10.13 GM candidate (17A362a) to both developers and public beta testers Thursday. GM, or Golden Master, candidates are software versions that could, and likely will, become the first shipping version. Apple said it will ship macOS High Sierra on September 25th.
Registered developers can find the update at the Apple Developer Connection. Devices that have already been provisioned for the developer beta cycle can find the update in Software Update in the Mac App Store.
If you’d like to participate in Apple’s public beta testing program you can sign up at the company’s website. Macs already provisioned for the public beta will find the release in the Mac App Store.
Unless a significant issue is found, macOS High Sierra 10.13 GM candidate (17A362a) will likely be the last release before the September 25th launch.