Through reverse engineering, developer James Laird was able to find the private key included in the Airport Express. To do so, he had to open one of them, dump the ROM to finds his way to the private key hidden by Apple.
James Laird first gave the key to VLC developers and then created an emulator and put int in open source. You can download it at this address. ShairPort works as a server for Apple's RAOP protocol (Remote Audio Output Protocol). The key on iTunes (client side), was discovered by now famous DVD Jon on October 2006
Until now, it was possible to stream music from a mac to an Airport Express. iTunes does it of course as well as Airfoil, which pays a license to Apple.
With ShairPort it is now possible to use or create hardwares that will emulate an Airport Express and it will be possible to stream music to them from a Mac or an iOS device.
The question now is how Apple will react? will it let it go?
It would be in the company's best interest, it would be a good sales argument, anyone who buys a Mac can now stream the music to a TV or a sound system (if it has adopted ShairPort).
Otherwise, it can decide not to accept it and can try to block the development of the software and keep on selling the hardware on which the company has its 30% margin.
In the mean time, if you want to use or test ShairPort, you can compile it rather easily on Linux. You will have to install the avahi libraries (implementation of Bonjour in Linux) and a few other elements that are listed in the instructions. On a Mac it is not hard either but it is not working at 100% we are currently running some tests and we will keep you updated.
