Rockbox

Description
Rockbox is an Open Source replacement firmware for iPods, the Archos Jukebox 5000, 6000, Studio, Recorder, FM Recorder, Recorder V2 and Ondio MP3 players.

Related wiki

 * AdaWiki occasionally mentions the x0xb0x and other sound-related open-source projects
 * Open Circuits occasionally mentions open source firmware for music players.