Caught this on Dan Barlow’s Diary.
I’ve been looking at Knoppix, and starting to learn enough about it to beat it into a shape I like. Knoppix is an ISO9660 image, which contains another, compressed, ISO filesystem. The inner filesystem is the root of the running system and contains about 2Gb of software. The outer filesystem gets mounted on /cdrom during the boot process and holds a few other files such as X root window images which are presumably put there for ease of alteration.
So, to hack it around you basically unpack the ISO, unpack the inner ISO, chroot into it and fiddle with dpkg/apt-get/whatever else, then pack it all back up again
