Amplitude is a servlet-based web application that allows you
to browse and play mp3's. It can be used in conjunction
with lame to re-encode mp3 files on the fly. This
allows http streaming of mp3's over low bandwith
connections such as upstream DSL
The PJS is a mp3-jukebox system written in Perl. It allows you to ripe and encode CDs (with CDDB support), exchange them between PJS's or play them. The player is a curses-application (like pine) and has many sophisticated features.