Beta Firmware

This is a documented list of beta firmwares Apple has provided to developers or were used for testing. To be able to use and download this software legally, you must have a $99/year Apple developer account.

Apple TV
Apple TV firmwares have two different version and build numbers, which can lead to confusion when referencing them. As such, the internal build number is the best way to refer to a specific firmware.
 * The "Marketing"/"Displayed" columns are what is reported on the Apple TV's "About" screen
 * The "Internal" column refers to the  and   keys in the IPSW's