At the presentation “Hey Siri”, Apple announced that Apple TV will work on tvOS. This is a new OS for Apple TV, based on iOS, so all features present on the latter iOS will be optimized for the large screen Apple TV.
The new OS will include the same developer tools as iOS and OS X: XCode. It also supports Metal, and has Game Center integration.
Apple has already partnered with some well-known developers who have created several apps specifically for tvOS, including Netflix, HBO Now, Hulu, Airbnb and many more. Apple also presented the new “Beats Sport” game exclusively for Apple TV. The game will be available on App Store for tvOS on the same day when Apple TV 4 goes on sale.