MusicBrainz!

We're on a mission to build the biggest and most comprehensive music database and marketplace. Imagine a site with discographies of all labels, all artists, all cross-referenced, and an international marketplace built off of that database. It's for the love of music, and getting closer every day

Gracenote, Inc., formerly called CDDB (Compact Disc Data Base), is a company that maintains and licenses an Internet-accessible database containing information about the contents of audio compact discs and vinyl records. It provides software and metadata to businesses that enable their customers to manage and search digital media. Gracenote provides its media management technology and global media database of digital entertainment information to the mobile, automobile, portable, home, and PC markets. Several computer software applications that are capable of playing CDs, such as Winamp, Sony Media Go, and iTunes, use Gracenote's CDDB technology. Gracenote’s database was originally created from and continues to receive voluntary contributions from users. This led to a licensing controversy when Gracenote became commercialized. »

freedb is a free CD and music data base service to look up textual metadata about music, audio or data CDs. This is done by a client which queries the freedb database. As a result, the client displays the artist, CD title, track list and some additional information. Clients are for example CD player, CD ripper and CD burn software. Freedb does not offer clients.

Demlo organizes your music library automatically and dynamically. It runs a chain of user-defined scripts using variables such as tags and file properties. This way it yields virtually unlimited customization power to the user.