UPDATE: XBMC has now been updated and renamed to KODI so all steps in this guide still apply just superficial name changes and logo changes are all that are marginally different.
For those that are unaware, XBMC is a magnificent, and open-source media centre and media platform. XBMC Media Centre for almost all platforms of mobile devices and desktop/laptop operating system. In the newest release of this software they support the ability to act as an AirPlay device, much like Apple TV. In this Instructable I will be showing how to activate this fun and great feature for any HTPC (Home theater PC) or any PC in general. I will be activating the AirPlay feature on both the computer platforms as well as the mobile iOS XBMC.
Step 1: Downloading XBMC for IOS
ATTAINING XBMC FROM CYDIA
If my instructions are not clear enough visit: http://wiki.xbmc.org/index.php?title=HOW-TO:Install_XBMC_for_iOS for more detail as this is not the main purpose of this Instructable.
If your device is not already jailbroken I will not go through that here. As soon as it is jailbroken you need to navigate to Cydia.
1 - Navigate to add a new source and add a new source with this URL: http://mirrors.xbmc.org/apt/ios
2 - When activated and verified click on the sources icon within your sources list and download and install the XBMC-iOS package.
3 - Once installed you should have a crisp install of XBMC on your iDevice.
Step 2: Activating AirPlay Service in XBMC for IOS
1- When opened you should see a screen with four quadrants representing different media categories.
2- in the bottom left of the screen you should see two buttons: exit, and settings. Press on settings.
3- In the settings portion you should see a list of adjustable areas of the program. Click on the bottom left one again, Services.
4- When in Services you will now see another list of Service Settings. The top three: General, UPnP, and Webserver. These are the ones we will use. The first one, General, is where you can adjust the name of your device as seen by other devices and XBMC parties.
5- After adjusting your device name if so desired click on UPnP. Click the first two options "on" and the third one is optional for other XBMC installations on LAN to control that particular installation. After turned on, go to Webserver menu.
6- Activate the first option to enable the ability to control XBMC from the remote app.
7- Once it is all complete go back to home by using the home button in the top left. Now use the before mentioned exit button and exit the program. Restart the app.
8- Now get on your other iOS device and select a file you wish to AirPlay.
9- Almost all files can be air played but videos in the actual "Videos" app. Mostly items in your camera roll. Activate AirPlay and select your XBMC devices name from the list and watch the magic!
10- The next step in this Instructable will be doing the same on the desktop version of XBMC.
Step 3: Activating AirPlay for XBMC Desktop Application
1- Launch XBMC. Simple enough.
2- Scroll to the farthest right option which should be: System.
3- Under the sub-menu, click on Settings.
4- Once within settings press on the Network menu.
5- Once there, stay on the Services menu. You should notice options very similar to the ones we changed before.
6- Activate "Share video and music libraries through UPnP" option, the one below it, and the one below that one.
7- The top three options and device names should be activated and customized to you liking.
8- Now find your file you wish to AirPlay to your desktop and select your device from the AirPlay devices list and it should work.
9- NOTE: This only works with items in camera roll and a select others. It does not behave like an actual Apple TV.