Knoppix is described as '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' and is a Linux Distro in the os & utilities category. There are more than 50 alternatives to Knoppix for a variety of platforms, including Linux, Windows, Self-Hosted, Mac and BSD apps. The best Knoppix alternative is Debian, which is both free and Open Source. Other great apps like Knoppix are Fedora, Arch Linux, Tails and Zorin OS.