Why not? AirPlay is a pretty high-level protocol, and it's got an ARM SoC, so the natural thing for Apple to do would be to use the ARM version of XNU with a minimal userland that has their AirPlay implementation and whatever codecs it needs.
At least, If someone handed me one of these dongles with a copy of the protocol spec and asked me to write the software for it, I'd do something similar except using Linux. (Sidenote: buildroot is great for creating embedded systems running Linux.)
At least, If someone handed me one of these dongles with a copy of the protocol spec and asked me to write the software for it, I'd do something similar except using Linux. (Sidenote: buildroot is great for creating embedded systems running Linux.)