Rockbox is an open-source operating system for MP3 players.

Today, I wanted to look online for a way to transfer songs to an iPod without using iTunes, and I found the Rockbox project. It's an open-source system that can be installed on many types of MP3 players, including the following models:

* Archos: Jukebox 5000, 6000, Studio, Recorder, FM Recorder, Recorder V2, and Ondio

* iriver: H100, H300, and H10 series

* Apple: 4th generation iPod (grayscale and color), 5th/5.5th generation (Video - 30GB and 60GB models only), 1st generation Nano, and 1st/2nd generation Mini (2nd generation Nano and 80GB Video 5.5th generation are not supported)

* iAudio: X5 (including X5V and X5L), M5 (including M5L)

* Toshiba: Gigabeat X and F series (the S model is not supported)

* SanDisk: Sansa E200 series (the R models are not supported)

* Additional models are in development