Sorry, I have to write these under the Red Hat Linux as there is no section on Knoppix for Linux distribution yet.
This Linux distribution runs entirely from a bootable CD. Data on the CD is uncompressed on the fly, allowing them to fit 2 GB worth of system and programs on one CD, including a complete X server, KDE, and large packages like OpenOffice and The Gimp. Since it runs solely off the CD, Knoppix makes an excellent portable Linux demo or system rescue disk, but its completeness makes it a good general purpose distribution as well.
KNOPPIX is a bootable CD or DVD with a collection of GNU/Linux software, automatic hardware detection, and support for many graphics cards, sound cards, SCSI and USB devices and other peripherals. KNOPPIX can be used as a productive Linux desktop, educational CD, rescue system, or adapted and used as a platform for commercial software product demos.
Here is a very useful link to download Linux images:
https://linuxiso.org/index.php