Knoppix
Knoppix is an operating system based on Debian designed to be run directly from a CD / DVD (Live CD) or a USB key (Live USB), one of the first of its kind for any operating system. When starting a program, it is loaded from the removable medium and decompressed into a RAM drive. The decompression is transparent and on-the-fly. Although Knoppix is primarily designed to be used as a Live CD, it can also be installed on a hard disk like a typical operating system. Computers that support booting from USB devices can load Knoppix from a live USB flash drive or memory card. There are two main editions of Knoppix: the traditional Compact Disc (700 megabytes) edition and the DVD (4.7 gigabytes) "Maxi" edition. Each of these main editions has two language-specific editions: English and German. Knoppix mostly consists of free and open source software, but also includes proprietary software
