So I am aware there are various alternatives to Apple TV for receiving Airplay Streams, such as XBMC, AirServer and Reflector.
These work to some degree but what I'd really like is a standalone solution, just some software that listens in the background until it receives the stream and then bounces into life. XBMC has too much extra fluff (media center features) and AirServer/Reflection require a license.
It seems the above solutions spawned by reverse engineering the Airplay protocol and I imagine Apple aren't too happy about this.