Freedb was a database of user-submitted compact disc track listings,[1] where all the content was under the GNU General Public License. To look up CD information over the Internet, a client program calculated a hash function from the CD table of contents and used it as a disc ID to query the database. If the disc was in the database, the client was able to retrieve and display the artist, album title, track list and some additional information.
Freedb was launched in 2001 based on the CDDB (Compact Disc DataBase) after it had been changed to a proprietary license and renamed "Gracenote".[2] As of 24 April 2006,[update] the Freedb database held just under 2,000,000 CDs.[3] As of 2007, MusicBrainz – a project with similar goals – had a Freedb gateway that allowed access to their own database.[4] The Freedb gateway was shut down on March 18, 2019.[5]
In 2020, Freedb was shut down by Magix, a German company that had acquired it in 2006.
:0
was invoked but never defined (see the help page).