Designed for the fourth and fifth-generation Apple TV, the tvOS 12 developer beta can be downloaded onto the Apple TV using a profile that's installed through the Xcode software. Subsequent betas can be downloaded via the software update mechanism on the Apple TV.
tvOS 12 introduces support for Dolby Atmos sound, which was activated in the second beta. Apple says that when tvOS 12 launches this fall, iTunes will be home to the largest collection of Dolby Atmos-supported movies.
Customers that have previously purchased movies that gain Dolby Atmos support will see free upgrades to their titles, much like the rollout of 4K support.
Building on single sign-on, a new zero sign-on feature will further simplify the cable authentication process. With zero sign-on, the Apple TV can detect a user's broadband network and automatically sign them into supported apps they receive through their accompanying cable subscription.
Zero sign-on will be available for Charter Communications customers this fall and will expand to additional cable providers in the future.
Aerial screensavers now include location information and there are new screensavers captured in collaboration with the International Space Station.
Other improvements tvOS-related improvements include AutoFill passwords from iPhone, an Apple TV Remote automatically added to Control Center on the iPhone or iPad, and Apple TV support on Home control systems like Control4, Crestron, and Savant.
tvOS 12 is available for developers and public beta testers to work out bugs and other issues ahead of a fall public launch.
Update: Apple has also made a new public beta of tvOS 12 available to public beta testers.