Debian GNU/Linux

There's only one option for Linux - ethernet into it using the Java code, Rio Music Manager Lite, (RMML). The Rio website has the latest supported version, but an even more recent version is probably available on the developer's private site, www.inzyme.com/rio. The RMML Java code was bulletproof for me, even when I did goofy stuff like editing the song titles, artist, album name and track numbers as RMML was uploading those files to the Karma 20. It's apparently well buffered, and automatically compares the song database in the Karma 20 to the one I just edited on the PC and only uploads the changes I made.

I was hoping I could just drag and drop files from the file manager via USB, upload files via the Karma's built-in web server, or ftp to it over the network, but it has a funky journaling file system so it's their way or the highway. But the Java is of course wonderfully machine independent, so it works very well with my Linux notebook.

Ethernet downloads are fast. Sound quality is excellent in this 1" X 3" X 3" player with 20 GB of storage (about 5000 songs). I like having my entire music collection in one tiny little device. The user interface is good for such a tiny device. Runtime is 15 hours on an internal lithium ion battery (bad news when it needs to be replaced because it's a custom battery). I like the fact that it has a charging cradle that also puts it on the local area network. I wish my latest digital camera had a charging cradle with USB communications.

I also like the fact that it plays Ogg and FLAC files as well as MP3. I hope Rio supports this device far into the future because it's firmware driven and that makes it flexible enough to keep up with the evolving digital audio standards.

Others have expressed a desire for a remote control and a protective carrying case. Both would be nice, but I'd particularly like the case. It'd be nice to be able to do active stuff without harming the Karma, yet also be able to quickly access the Karma's user interface as needed.