The MusicBrainz (libmusicbrainz) C/C++ Library by MusicBrainz is a client library for developers. Using this library, developers can add MusicBrainz look-up capabilities to their applications. The MusicBrainz database contains a huge amount of music metadata, which is maintained by the MusicBrainz community.
Two days, a room full of hackers and one theme: music. This is the premise behind the Stockholm Music Hack Day, which resulted in 31 projects including hardware hacks, mobile, web and desktop applications. A number of the web applications are live and available for anyone to use.