I just installed Rockbox, an open source firmware for music players, on my Cowon iAudio M5.
I’ve owned this portable music player for a couple of years, originally purchasing it because it is wonderfully compatible with Linux and mounts as a USB Mass Storage device and plays nearly every common audio filetype, including all the ones I had/have on my hard drive.
I liked the original firmware that Cowon provided and never had a problem with it. However, me being me, I had some free time and needed a project, so I downloaded Rockbox and installed it today. I expected this would be a detailed and complicated process, as installing custom firmware often is (eg. like the first time I installed dd-wrt on my Linksys wrt54g v2). It wasn’t. The whole process took ten minutes, and that includes the time I took to read the installation instructions. Wow!
Then, I turned the player on and began to play. Immediately I began to ask myself why I hadn’t done this ages ago. Rockbox has so many more features and configurability, plus (more importantly) it works well. I’m impressed!