All sources extract and refers from wikipedia

Linux (IPA pronunciation: /ˈlɪnʊks/) is a Unix-like computer operating system family. Linux is one of the most prominent examples of free software and of open source development; its underlying source code is available for anyone to use, modify, and redistribute freely.^[1]

The first Linux systems were completed in 1992 by combining system utilities and libraries from the GNU project with the Linux kernel, which led to the coining of the term GNU/Linux.^[2] From the late 1990s onward Linux gained the support of corporations such as IBM,^[3] Sun Microsystems,^[4] Hewlett-Packard,^[5] and Novell.^[6]

Predominantly known for its use in servers, Linux is used as an operating system for a wider variety of computer hardware than any other operating system, including desktop computers, supercomputers,^[7] mainframes, and embedded devices such as cellphones. Linux is packaged for different uses in Linux distributions, which contain the kernel along with a variety of other software packages tailored to requirements.

Ubuntu (IPA pronunciation: /u’buntu/) is a widely used Linux distribution predominantly targeted at personal computers. Based on Debian GNU/Linux, Ubuntu concentrates on usability, regular releases, ease of installation, and freedom from legal restrictions. Ubuntu is sponsored by Canonical Ltd., a private company founded by South African entrepreneur Mark Shuttleworth.

The name of the distribution comes from the Zulu and Xhosa concept of ubuntu, which means “I am what I am because of who we all are”. Ubuntu’s slogan – “Linux for Human Beings”, encapsulates one of its main goals – making Linux more available and easy to use.

The most recent version, Ubuntu 7.04 (Feisty Fawn), was released on April 19, 2007. Version 7.10 (Gutsy Gibbon) is scheduled for release on October 18, 2007.^[3]

Fedora (previously called Fedora Core) is an RPM-based Linux distribution, developed by the community-supported Fedora Project and sponsored by Red Hat. It aims to be a complete, general-purpose operating system that contains only free and open source software.^[1][2] Fedora is derived from the original Red Hat Linux distribution, and it is intended to replace the consumer distributions of Red Hat Linux aimed towards home users. Support for Fedora comes from the greater community; while Red Hat employs many of the Fedora developers, it does not provide official end-user support for the distribution. New releases of Fedora come out every six to eight months.

openSUSE is a community project, sponsored by Novell, to develop and maintain a general purpose Linux distribution. After acquiring SUSE Linux in January 2004,^[1] Novell decided to release the SUSE Professional product as a 100% open source project, involving the community in the development process.^[2] The initial release was a beta version of SUSE Professional 10.0 and as of February 2007 the current stable release is openSUSE 10.2.^[3]

openSUSE provides, beyond the distribution, a web portal for community involvement. The community assists in developing openSUSE collaboratively with representatives from Novell by contributing code through the open Build Service, writing documentation, designing artwork, fostering discussion on open mailing lists and in Internet Relay Chat channels, and improving the openSUSE site through its wiki interface. It is one of Novell’s stated goals to market openSUSE as the best, easiest distribution for all users.^[4]

Like most distributions it includes both a default graphical user interface (GUI) and a command line interface option; it allows the user (during installation) to select which GUI they are comfortable with (either KDE or GNOME), and supports thousands of software packages across the full range of open source development.

Red Hat, Inc. (NYSE: RHT) is one of the largest and most recognized companies dedicated to open source software. It is also the largest distributor of the GNU/Linux operating system^{[citation needed]}. Red Hat was founded in 1993 and has its corporate headquarters in Raleigh, North Carolina with satellite offices worldwide. ^[1]

The company is best known for its enterprise-class operating system, Red Hat Enterprise Linux and more recently through the acquisition of open source enterprise middleware vendor JBoss. Red Hat provides operating system platforms along with middleware, applications, and management solutions, as well as support, training, and consulting services.

The GNU Project is a free software project, announced in 1983 by Richard Stallman. It initiated the GNU operating system, software development for which began in January 1984. GNU is a recursive acronym that stands for “GNU’s Not Unix”.

The founding goal of the project was, in the words of its initial announcement, to develop “a sufficient body of free software [...] to get along without any software that is not free.”

The first milestone was to make a free software operating system. To make this happen, the GNU project began working on an operating system called the GNU system. This goal of making a free software operating system was achieved in 1992 when the last gap in the GNU system, a kernel, was filled by a third-party Unix-style kernel called “Linux” being released as free software.

The GNOME project is an international effort to create an easy-to-use computing platform built entirely from free software. This goal includes creating tools which help developers write new stand-alone application software, selecting applications for inclusion in the official product, and working on what is known as the desktop environment — the programs which manage application launching, file handling, and window and task management.

A great deal of software is created or hosted under the umbrella of the GNOME project, some of which is collected and released as GNOME. GNOME is used in conjunction with an operating system such as Linux or Sun Microsystems’ Solaris, to create a fully functional computer system.

GNOME is part of the GNU operating system, and is its official desktop environment. The official pronunciation of the name is /gəˈnoʊm/ with a hard “G”, although /noʊm/ (as in the English word “gnome”) is also in common usage.

KDE (K Desktop Environment) (IPA: [ke.di.i]) is a free software project which aims to be a powerful system for an easy-to-use desktop environment. The goal of the project is to provide basic desktop functions and applications for daily needs as well as tools and documentation for developers to write stand-alone applications for the system. In this regard the KDE project serves as an umbrella project for many standalone applications and smaller projects that are based on KDE technology, such as KOffice, KDevelop, Amarok and K3b.

The KDE logo is a “K” over a cogwheel and the project’s mascot is a green dragon named Konqi. Konqi can be found in various applications, including when the user logs out and in the “About KDE” screen.