A music player and tag editor. Quod Libet is a music library management program. Rather than categorize songs by genre, artist, and album, it lets you search and display them however you want. It supports regexp-based searches, album cover display, tag editing, ReplayGain, multimedia keys, and an OSD.
Also included is Ex Falso, a tag editor that has the same editing features found in Quod Libet, but does not play audio files.