The Vorbis General Audio Compression Codec (development files)

 Ogg Vorbis is a fully open, non-proprietary, patent-and-royalty-free,
 general-purpose compressed audio format for audio and music at fixed
 and variable bitrates from 16 to 128 kbps/channel.
 .
 This package contains the header files and documentation needed to develop
 applications with libvorbis.