Built on Kayak HTTP Server Framework v0.7.2-3 (http://kayakhttp.com/). Slightly modified to fit airplay/ios communication behavior. Source included as part of library.
Uses System.Runtime.Serialization.Plists (https://github.com/ChadBurggraf/plists-cs) for decoding binary plist data. Source included as part of library.
Uses code from Plist.net (http://sourceforge.net/projects/plistdotnet/) for encoding XML data. Source included as part of library.
Uses zeroconfignetservices (http://code.google.com/p/zeroconfignetservices/) to publish service. (DLL included in lib folder)
Everything I know about the Airplay protocol has been learned by reading sources and monitoring HTTP traffic from:
* AirPlayer Python lib (https://github.com/PascalW/Airplayer) 
* Air Stream Player For Windows (http://code.google.com/p/airstream-media-player/).
Exception handling/logging has not been properly implemented. Exceptions may get swallowed and/or crash server.
Should be pretty easy to clean up.
This library supports streaming video/photos from IOS device. Audio streaming uses a different protocol and is not supported at all by this library.
Check out Shairport4w for streaming of audio from IOS device. https://sourceforge.net/projects/shairport4w/