Linux (pronounced LIH-nuks) is an operating system for computers, comparable to Windows or Mac OS X. It was originally created starting in 1991 by Finnish programmer Linus (pronounced LEE-nus) Torvalds with the assistance of developers from around the globe. Linux resembles Unix, an earlier operating system, but unlike Unix, Linux is both Free Software and open source software -- that is, you can not only download and run it on your computer, but also download all the source code the programmers created to build the operating system. You can then modify or extend the code to meet your needs.

Linux runs on a wide variety of hardware platforms, from huge mainframes to desktop PCs to cell phones. It is licensed under the Free Software Foundation\'s GNU Project\'s GNU General Public License, version 2, which lets users modify and redistribute the software.

You can think of Linux as having two parts -- a kernel, which is the basic interface between the hardware and other system software, and the functions that run on top of it, such as a graphical user interface (GUI) and application programs.

No single company sells Linux. Because it\'s open source software, anyone can package Linux with some programs and utilities and distribute it. The different "flavors" of Linux are called distributions. You can get information about some of the most popular distributions from our distributions page. A comprehensive resource for distributions is DistroWatch.com.

Many Linux distributions are designed to be installed on your computer\'s hard drive, either as a sole operating system, or in a dual boot configuration with another OS, which lets you choose which operating system to run every time you start your computer. Others are designed to run as live CDs that boot from removable media -- typically CDs, but there are also live DVD distributions, and even ones that boot from diskettes and USB storage media. Live distributions can be useful because they let you run a different operating system without affecting any of the contents of your hard drive.

If you\'re a Windows user to whom Linux is completely new, trying it out might sound daunting. For you we explain in a separate article how you can test Linux without altering your Windows computer, how to install Linux while preserving all of your Windows programs and files, and how to choose what Linux flavor suits your needs best.

The Linux desktop

Part of what makes Linux useful on your computer is its graphical user interface. The GUI gives Linux a "look and feel" with clickable icons and widgets, as well as screen borders, scroll bars, and menus that the user can manipulate and customize. This "point and click" environment makes the operating system more intuitive by presenting interface options in an attractive visual layout that doesn\'t require knowledge of textual commands. Without the GUI, Linux (or any operating system) requires users to type commands in a procedure that is known as the Command Line Interface (CLI).

While most operating systems don\'t let you choose the user interface you want, Linux gives you a choice of several. Most of them are more than just graphical interfaces -- they are truly complete desktop environments that come with tools, utilities, games, and other applications to make the user\'s computing experience a richer one. Two of the most popular desktop environments that work with Linux are KDE and GNOME.

KDE stands for K Desktop Environment. KDE runs on any Unix operating system, including Linux. All of the source code for KDE is licensed under the terms of the GNU General Public License, which means that anyone can access and change KDE to suit specific purposes. KDE comes packaged with most Linux distributions and includes standardized menus, toolbars, and color schemes, as well as a complete help system, networking tools, graphics and multimedia applications, and a complete office productivity solution, and dozens of other software tools. The entire KDE project is supported by the free software development community and is provided to Linux users at no cost.

GNOME (pronounced guh-NOME), the GNU Network Object Model Environment, is another ubiquitous GUI or desktop environment for Linux. It is also licensed under the terms of the GNU General Public License, which means it is freely available, along with the source code, for use on any Unix-based operating system. GNOME comes packaged with just about every Linux distribution. It is a part of the GNU project, which created the GNU operating system, parts of which are included with all standard Linux distributions.

Like KDE, the GNOME desktop environment includes more than just toolbars, icons and menus. Help files, networking tools, games, and productivity applications like GNOME Office round out the free software offering.

Other GUIs that work with Linux include:

XPDE desktop environment - "tries to make it easier for Windows XP users to use a Linux box."

Xfce - "lightweight desktop environment for various *NIX systems. Designed for productivity, it loads and executes applications fast, while conserving system resources."

Enlightenment - "advanced graphical libraries, tools, and environments."

IceWM - "The goal of IceWM is speed, simplicity, and not getting in the user\'s way."

Blackbox - "Blackbox is the fast, lightweight window manager for the X Window System you have been looking for, without all those annoying library dependencies."

Window Maker - "Window Maker is an X11 window manager originally designed to provide integration support for the GNUstep Desktop Environment."

FluxBox - "A fast compact window manager based on the Blackbox, but offering more features."

The command line

One thing all the desktop environments have in common is that they let users access Linux commands; you don\'t have to use a mouse to perform every operation. It may be faster and easier to perform some operations by typing in one or more commands, as users used to have to do on PCs under DOS 20 years ago.

Each desktop environment has a different way to get to a command prompt. Often, you\'ll open a window that lets you type commands. In GNOME, that application is called GNOME Terminal; in KDE, it\'s Konsole.

We\'ve prepared a brief introduction to the command line. A good site for further learning is LinuxCommand.org.

Desktop applications

Like any operating system, Linux supports a wide range of desktop applications. Typical programs include those for email, office software, playing music and video, personal information management, network communications such as instant messaging and Internet Relay Chat, and file sharing.

Gaming

Linux is no stranger to gaming. Linux distributions almost always include games; the GNOME Games package, for example, features 16 arcade and puzzle games, and the KDE Games Center includes games from the arcade, board, card, dice, logic, strategy, and toy genres. If the distributions don\'t contain what you\'re looking for, you can turn to commercial sites such as Linux Game Publishing and Tux Games, or you can buy games directly from small companies, independent publishers, and bedroom coders. If games designed for Microsoft Windows or home gaming systems are what you\'re after, several available emulators may be able to help. For more information on the numerous games available to Linux users and how to obtain them, see Enjoying games with GNU/Linux.

This is not the end

Coming soon, we\'ll be adding to this document to talk about different categories of desktop and server applications, programming tools, training, and support. We welcome your input on what you think new Linux users should know about. If you are a new Linux user with a question, please ask it in our forums.