"Interestingly, one of the companies mentioned in the HipZip's
about-the-player menu is Xiphophorus, the open-source outfit
responsible for, among other things, the Ogg Vorbis audio codec.
But the HipZip can't actually play Vorbis files."
"This could change. The HipZip runs the Dadio operating
system from Interactive Objects. Dadio is based on Red Hat's eCos
embedded-systems open source operating system, designed for
small-memory devices that don't need the features (or the bulk) of
Linux. Because the player's a little computer, not just a
fixed-function bundle of non-writable chips, you can update its
firmware to add features."
"If you want tons of music on the go, though, the HipZip is
pretty much the only option -- MP3 CD players are bigger and
clunkier, and they don't like being bounced around, and you can't
just shuffle files on and off whenever you like."