Not doing really ATV, but watching sometimes the ATV Relais with the software ATV Monitor (ATV Player) or VH MultiCamera Studio.

ATV Monitor is a Streaming Player for all Audio/Video Streams from Internet.

Here are some examples:

VH Multi Camera Studio also is a Streaming Player for all Audio/Video Streams from Internet.

Here an example:

You can find on my LiveATV page some Live ATV Relais.