Backup to filesystems or CD R/Ws as a “Jukebox”-like device with Legato NetWorker. The purpose is to use a Jukebox of for instance 10 R/W CD Records instead of a StorageTek SILO, which might be a bitter cheaper for the common user.
The Rockbox project produces an open source firmware replacement for portable Digital Music Players, currently supporting Archos, iriver and iPod models with more platforms being worked on.
eGott is a standalone jukebox server for Linux. It is remotelly controllable via native protocol. It supports multiple simultaneous users, multiple playlists, etc... Native client in Java is also available.
The Nomad Jukebox File system njbfs is a Linux file system for the Creative Nomad Jukebox. Using automount capability, you can 'cd' to your Nomad Jukebox, read and write tracks, and even ordinary files can be stored on your Jukebox.