Hyperion is an opensource 'AmbiLight' implementation controlled using the RaspBerry Pi running Raspbmc. The main features of Hyperion are:

• Low CPU load. For a led string of 50 leds the CPU usage will typically be below 1.5% on a non-overclocked Pi.
• Json interface which allows easy integration into scripts.
• A command line utility allows easy testing and configuration of the color transforms (Transformation settings are not preserved over a restart at the moment...).
• Priority channels are not coupled to a specific led data provider which means that a provider can post led data and leave without the need to maintain a connection to Hyperion. This is ideal for a remote application (like our Android app).
• HyperCon. A tool which helps generate a Hyperion configuration file.
• XBMC-checker which checks the playing status of XBMC and decides whether or not to capture the screen.
• Black border detector.
• A scriptable effect engine.
• Generic software architecture to support new devices and new algorithms easily.

More information can be found on the wiki or the Hyperion topic on the Raspbmc formum.

The source is released under MIT-License (see http://opensource.org/licenses/MIT).