While Apple's AirPlay feature introduced in iOS 4.2 allows users to stream certain video content from their iOS devices to the new Apple TV, users have been wondering if the service will ever be extended to allow content to be streamed to their Macs in a similar fashion. In addressing the question of whether such an implementation would be difficult, TUAW's Erica Sadun has put together an alpha version of a Mac OS X application known as "AirPlayer" that does exactly that.
What AirPlayer does is create and advertise a custom Bonjour AirPlay service that pretends to be an Apple TV. Bonjour is Apple's zero configuration networking solution for allowing devices and applications to communicate with each other over local area networks. When Apple created AirPlay, it basically set up a new way for Apple TV to interact with iOS using Bonjour communications.
The functionality could in theory also be supported on Windows PCs as Apple offers Bonjour for Windows, although Sadun notes that she is not likely to attempt to build a Windows version anytime soon.
Interested users can download the ad-supported alpha version for Mac OS X from Sadun's website to test out the functionality. Users' iOS devices do not need to be jailbroken for the functionality to work, although some tools such as AirVideoEnabler that can extend AirPlay functionality to more iOS apps do require jailbreaking.
AirPlayer remains an early proof-of-concept release, and users are of course advised that there may be bugs and other quirks associated with the application.