Ogg

Ogg is a project to create an open source, patent-free multimedia system. It was created by the Xiph.org Foundation.

Currently, the project includes several specifications:
 * the Ogg bitstream format, which can encapsulate the audio/video streams and acts as a container
 * Vorbis, a general-purpose audio codec
 * Theora, a video codec which is still in the alpha stage of development
 * FLAC, a lossless audio codec
 * Speex, an audio codec designed for speech