CoreVorbis is completely free and open-source. It is released under the GNU GPL and QPL license.

Vorbis is a fully open, non-proprietary, patent-and-royalty-free, general-purpose compressed audio format for mid to high quality (6kHz-96kHz, 16+ bit, polyphonic) audio and music at fixed and variable bitrates from 2 to 256 kbps/channel. This places Vorbis in the same competitive class as audio representations such as MPEG-4 (AAC), and similar to, but higher performance than MPEG-1/2 audio layer 3 (MP3), TwinVQ (VQF), WMA and PAC.