Rockbox
Rockbox is an Open Source replacement firmware for portable digital audio players including the Archos Jukebox 5000, 6000, Studio, Recorder V1, FM Recorder, Recorder V2 and Ondio MP3 players.
Development of Rockbox for the iriver H1xx, H3xx and H10 series of players as well as the iAudio X5, M5, and M3, iPod 1G, 2G, 3G, 4G greyscale, Color/Photo, 1G and 2G mini, 1G nano and Video (5G and 5.5G), Toshiba Gigabeat F and X, Sansa e200, e200R and c200, Olympus m:robe 100, and others is underway.
Rockbox is a complete rewrite and uses nothing from the original firmware. It boasts numerous features while remaining easy to use.
Visit members of the Rockbox community and see Rockbox running on a variety of devices at booth 55.