The software is intended for professional musicians as well as light computer music users and has so far sold on the idea that the only limits are the users' own skills.[4] Japanese musical groups Livetune of Toy's Factory and Supercell of Sony Music Entertainment Japan have released their songs featuring Vocaloid as vocals. Japanese record label Exit Tunes of Quake Inc. also have released compilation albums featuring Vocaloids.[5][6] Artists such as Mike Oldfield have also used Vocaloids within their work for back up singer vocals and sound samples.[7][8]