VLC Media Player
Open Source
A free and opensource very popular media player. VLC Media Player supports a wide variety of media formats and known for its stability.
Napster
Commercial
Napster is a peer-to-peer (P2P) file sharing Internet service that emphasized sharing digital audio files, typically songs, encoded in MP3 format.
Compare Sonata with alternatives
Compare VLC Media Player and Sonata and decide which is most suitable for you.