Schroedinger (or schro for short) is an implementation of the Dirac and SMPTE VC-2 video compression specification. Dirac was developed by BBC Research & Development (http://www.bbc.co.uk/rd/) as an open technology with open licensing.
Schroedinger is the C library implementing video encoding and decoding. Most end users will want to use an application that uses the Schroedinger library for encoding and decoding Dirac streams. A few such applications are Totem, VLC, and Mplayer.
In addition, media frameworks such as GStreamer and decoding libraries such as ffmpeg can be configured to use Schroedinger either internally or via plugins.