Ex Falso / Quod Libet - A Music Library/Editor/Player

Quod Libet is a music management program.  It provides several different 
ways to view your audio library, as well as support for Internet radio and 
audio feeds.  It has extremely flexible metadata tag editing and searching 
capabilities.

Ex Falso is a tag editor with the same tag editing interface as Quod Libet, 
but it does not play files.

Extra Plugins are also available from the Quod Libet homepage.