Vorbis is a free and open-source software project headed by the Xiph.Org Foundation. The project produces an audio coding format and software reference encoder/decoder (codec) for lossy audio compression. Vorbis is most commonly used in conjunction with the Ogg container format and it is therefore often referred to as Ogg Vorbis.
Vorbis is a continuation of audio compression development started in 1993 by Chris Montgomery. Intensive development began following a September 1998 letter from the Fraunhofer Society announcing plans to charge licensing fees for the MP3 audio format. The Vorbis project started as part of the Xiphophorus company's Ogg project (also known as OggSquish multimedia project). Chris Montgomery began work on the project and was assisted by a growing number of other developers. They continued refining the source code until the Vorbis file format was frozen for 1.0 in May 2000. Originally licensed as LGPL, in 2001 the Vorbis license was changed to the BSD license to encourage adoption with the endorsement of Richard Stallman. A stable version (1.0) of the reference software was released on July 19, 2002.
The Xiph.Org Foundation maintains a reference implementation, libvorbis. There are also some fine-tuned forks, most notably aoTuV, that offer better audio quality, particularly at low bitrates. These improvements are periodically merged back into the reference codebase.
Vorbis is named after a Discworld character Exquisitor Vorbis in Small Gods by Terry Pratchett. The Ogg format, however, is not named after Nanny Ogg, another Discworld character; the name is in fact derived from ogging, jargon that arose in the computer game Netrek.
The Vorbis format has proven popular among supporters of free software. They argue that its higher fidelity and completely free nature, unencumbered by patents, make it a well-suited replacement for patented and restricted formats.
Vorbis has different uses for consumer products. Many video games store in-game audio as Vorbis, including Amnesia: The Dark Descent, Grand Theft Auto: San Andreas, Halo: Combat Evolved, Minecraft, and World of Warcraft, among others. Popular software players support Vorbis playback either natively or through an external plugin. A number of websites, including Wikipedia, use it. Others include Jamendo and Mindawn, as well as several national radio stations like JazzRadio, Absolute Radio, NPR, Radio New Zealand, and Deutschlandradio. The Spotify audio streaming service uses Vorbis for its audio streams. Also, the French music site Qobuz offers its customers the possibility to download their purchased songs in Vorbis format, as does the American music site Bandcamp.
Listening tests conducted through 2014 showed Vorbis performed significantly better than many other lossy audio formats in that it produced smaller files at an equivalent or higher quality while retaining computational complexity comparable to other MDCT formats such as AAC and Windows Media Audio.
Listening tests have attempted to find the best quality lossy audio codecs at certain bitrates. Some conclusions made by listening tests: