Quod Libet

Website: http://code.google.com/p/quodlibet/

Version: 1.0

Engine: Gstreamer

 

It's designed around the idea that you know how to organize your music better than we do. It lets you make playlists based on regular expressions (don't worry, regular searches work too). It lets you display and edit any tags you want in the file. And it lets you do this for all the file formats it supports -- Ogg Vorbis, FLAC, MP3, Musepack, and MOD.

http://code.google.com/p/quodlibet/

 

Various windows to browse your collection.

click for bigger

 

click for bigger

It does support the composer tag but list them as part of 'people' so artist and composers in one list.

Lots of plugins

You can customize the browser.

Good tagging options