"A bootable business card, or BBC, is a complete operating
system contained on a business-card-sized CD-ROM. These mighty
mites normally focus on utility rather than usability. They are
usually self-contained rescue and recovery tools which can be used
to retrieve information or modify damaged configurations on
machines with non-functional operating systems installed. They
require no installation, running live from CD-ROM. They don't care
what operating system is present on the hard drive. And they do
nothing to modify the contents of the drive unless you explicitly
choose to do so.
"Because a business card CD-ROM can only hold about 50 MB of
software, the emphasis is on keeping things small. You won't find
the typical debates regarding KDE versus GNOME on BBCs. Both of
those desktop solutions require far too much disk space to be
useful in this arena. Instead, you can expect to employ lightweight
window managers like Fluxbox or Blackbox..."