Linux

Linux is a Unix-like computer operating system. Linux is one of the most prominent examples of free software and open source development: typically all underlying source code can be freely modified, used, and redistributed by anyone.

Distributions

 * Arch Linux
 * Damn Small Linux
 * Debian
 * Fedora
 * Gentoo
 * Kubuntu
 * openSUSE
 * PCLinuxOS
 * Puppy Linux
 * Red Hat
 * Slackware
 * SUSE
 * Mandriva
 * Ubuntu
 * Xubuntu

Links

 * Wikipedia Article