Linux - Open Source Operating System - CentOS - Ubuntu - Debian - Redhat

Debian is a computer operating system composed of free and open source software. The primary form, Debian GNU/Linux, is a popular and influential Linux distribution. Debian is known for strict adherence to the Unix and free software philosophies as well as using open development and testing processes. Debian can be used as a desktop as well as server operating system.

Fedora is an RPM-based, general purpose operating system built on top of the Linux kernel, developed by the community-supported Fedora Project and sponsored by Red Hat. Fedora's mission statement is: "Fedora is about the rapid progress of Free and Open Source software."

One of Fedora's main objectives is not only to contain free and open source software, but also to be on the leading edge of such technologies. Also, developers in Fedora prefer to make upstream changes instead of applying fixes specifically for Fedora -- this ensures that updates are available to all Linux distributions.

Ubuntu is a computer operating system based on Debian GNU/Linux, a popular Linux distribution. Its name comes from the Zulu word "ubuntu", translated as "humanity to others", describing the ubuntu philosophy: "I am what I am because of who we all are", a positive aspect of community. Ubuntu's goals include providing an up-to-date, stable operating system for the average user, with a strong focus on usability and ease of installation. Ubuntu has been rated as the most popular Linux distribution for the desktop, claiming approximately 30% of desktop Linux installations in 2007. Ubuntu is also used on some high profile servers, including those belonging to the Wikimedia Foundation.