LinuxDevCenter.com: Using and Customizing Knoppix [Nov. 20, 2003]: "The basic idea of making a Knoppix CD is to gather what you want on the CD by simulating it on the hard drive. You should be able to edit installed software and test your creation by rebooting the machine from the hard drive, via a bootloader, instead of wasting time burning it to a CD. This development environment mimics the CD, except it's significantly faster. Remember, this is not a standard Linux installation! Even though you are booting from the hard drive, you are in fact emulating an OS that is installed on a CD. When booted, the filesystem cannot be changed; it is read-only. "