Linux

An open source clone of the UNIX operating system. Technically speaking only the OS kernel is supposed to be called Linux but it has become customary to refer to any OS distribution that is based on it and has a UNIX style userland by the name.

Linux kernel

The Linux kernel is also used by a few operating systems that do not have a UNIX style userland on top of them, the best known of these is Android

Known Linux distributions

• Debian
  • Knoppix
    • Damn Small Linux
  • Sparky Linux
• Gentoo
  • ChromeOS
  • Korora
• Linspire
• Mandrake
  • Mandriva
    • Mageia
    • PCLinuxOS
• Mint
• Oracle Linux - Red Hat fork
• Red Hat
  • Fedora
  • CentOS
  • Scientific Linux
• Slackware - Ruled the roost in the mid 90's but has declined since. Very UNIX like.
• Suse
  • OpenSuse
• Ubuntu - Currently the most popular distribution.
  • Elementary OS
  • Kbuntu
  • Lubuntu
    • Peppermint Linux
• Yggdrasil - The first Linux distribution.