Rockbox is an open source firmware for mp3 players, written from scratch. It runs on a wide range of players:
* Apple: 1st through 5.5th generation iPod, iPod Mini and 1st generation iPod Nano
(not the Shuffle, 2nd/3rd gen Nano, Classic or Touch)
* Archos: Jukebox 5000, 6000, Studio, Recorder, FM Recorder, Recorder V2 and Ondio
* Cowon: iAudio X5, X5V, X5L, M5 and M5L
* iriver: H100, H300 and H10 series
* SanDisk: Sansa c200, e200 and e200R series
* Toshiba: Gigabeat X and F series (not the S series)
* More players are in development
One of the most undervalued software of our times RockBox can really make an iPod rock. Kudos to team of RockBox to hack through closed firmwares and come up with an excellent replacement for many known music player software (in layman terms). RockBox to a music player is like Linux for a computer. RockBox understands the machine and helps play music in various file formats on your electronic music player. It can completely replace the proprietary (and time times completely lackluster) software running on your player.
Check out why RockBox is better than the original: http://www.rockbox.org/twiki/bin/view/Main/WhyRockbox
Other than supporting larger number of file formats which it can play on a player, it also significantly improves the player efficiency. Other than a host of benefits you also have the ability to give a unique face lift to your player through its themes and display options.
I have personally installed RockBox on my 80GB iPod (which also frequents as my USB drive). With RockBox I dont need iTunes or a separate manager for managing my songs on the iPod. I just copy the songs directly from my Windows box to the iPod drive. This has immense benefits as I can now share the songs with anyone I want just as I would do from a portable drive and also play the same songs on my ipod. RockBox also has its own video player which means I don't have to convert the videos (.avi) to see them on the iPod, I can directly play them without any conversion.
My remorse with RockBox and iPod has been its hunger for power. The battery life seems to be much less than what I would get from Apple's firmware. The RockBox team seems to be working on it and I more hopeful about them resolving the problem than Apple freeing up the player from their proprietary format.
Installation might seem a bit difficult but if you follow the simple and excellent procedure as mentioned in the documentation I am sure you will be able to start RockBox in a few minutes.
If you are concerned about the warranty I would suggest that you don't try RockBox. But if you are brave enough I will say that you can always reformat the iPod later with its original software to get it back as new (on the software front atleast). So go ahead and have a rocking time with RockBox on your MP3 player or iPod.