What is Linux?
Linux starts here
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
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.
Linux.com did not create and does not sell Linux. We simply write about Linux and other
open source software. We're part of SourceForge, Inc., which also maintains
SourceForge.net, Slashdot, and ITManagersJournal.com.
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
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
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
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
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
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.
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.
While there are too many Linux distributions for us to include them all, here are some of
the most popular Linux distros, along with their download pages.
CentOS - The Community Enterprise Operating System
CentOS is a distribution based on source RPMs from Red Hat Enterprise Linux (RHEL),
and strives to be 100% binary compatible with RHEL.
CentOS download mirrors
Damn Small Linux
Damn Small Linux is a live CD distribution that fits on a business card CD and is light
enough to run on a 486 computer with as little as 16MB of RAM.
Damn Small Linux mirrors, BitTorrent
The Debian distribution and Debian Project are governed by a social contract that
requires that OSes produced by Debian will be 100% "free," as determined by the Debian
Free Software Guidelines (DFSG).
Debian download page
Fedora, formerly known as Fedora Core, is a Linux distribution sponsored primarily by
Red Hat, with significant community participation. The Fedora Linux distro produced by
the Fedora Project was based on the original Red Hat Linux distribution and is made up
entirely of free and open source software.
Fedora mirrors, BitTorrent
Note that the Fedora Project produces several "spins," including live CDs, DVDs
containing the full set of Fedora packages, and boot ISOs for Internet installations of
Fedora. See the installation guide to figure out which version of Fedora is right for you.
Freespire is the community-oriented version of Linspire.
Freespire download, BitTorrent
Gentoo is a source-based distribution, meaning all of its programs can be compiled from
source code rather than installed as binary packages. That makes it highly configurable.
Because the operating system and all of its applications can be compiled for the specific
machine architecture it's installed on, Gentoo can perform extremely well. Gentoo is
available for at least eight 32- and 64-bit hardware platforms. The distribution is more
complicated to install than many others, but an active user community can help those
who wish to tackle it.
Gentoo uses a package system called Portage that resembles FreeBSD's Ports. It lets you
quickly install more than 10,000 pre-built applications.
Gentoo download page
Knoppix is one of the most popular live CD Linux distros.
Knoppix mirror network, BitTorrent, eMule
Linspire is an Ubuntu-based distribution whose chief distiguishing feature is the ease of
installing new software with its Click-N-Run (CNR) installation utility. While Linspire
costs $50, its sibling Freespire is free.
Linspire purchase page
Linux Mint is an Ubuntu-based distribution that comes in two main CD versions. The
Light Edition avoids non-free patented software. The Full Edition includes proprietary
plugins and codecs. Both use the GNOME desktop environment by default. You can also
download a KDE Community Edition DVD or miniKDE Community Edition CD, or an
XFCE Community Edition CD.
Mandriva Linux, formerly known as MandrakeLinux, is an RPM-based distro that was
originally designed to be binary compatible with Red Hat Linux. Mandriva produces
versions of its Linux distribution for consumer desktops, corporate servers, and for high
performance clusters. Some, but not all, versions of Mandriva are free to download.
Mandriva download page
The openSUSE project is sponsored by Novell to create a base for the SUSE Linux
distribution it sells and supports. The openSUSE distribution is worked on by Novell
employees and community members, and is suitable for desktop and server use.
You can find openSUSE downloads at download.opensuse.org, but it may be a little
confusing. The project offers multiple ISOs for CD installation, DVD installation, and
network installation. You can also find BitTorrents for the various downloads, and a live
DVD. If you're not quite sure what you need, visit the download guide, which explains
the release table, and what development versions may be available and how stable they're
likely to be.
PCLinuxOS is a popular Linux distribution distributed as a live CD that can be installed
to your hard drive. Originally based on Mandriva, PCLinuxOS is now a solid distro in its
own right that uses APT and Synaptic to manage packages, and some of the original
Mandriva administration tools.
PCLinuxOS download mirrors, BitTorrent
Puppy Linux was written from scratch with two goals in mind: speed and ease of use. At
boot time the entire system loads into RAM and runs from there, which significantly
boosts the system's overall speed, and lets you run Puppy on a diskless workstation or
thin client. It downloads in only 90MB, and can run as a live CD. It also comes with a
remastering script for creating derivative distros, which other developers have used to
build Puppy-based distros (called puplets), including NOP, GrafPup, and EduPup.
Puppy Linux download page
Sabayon Linux is based on Gentoo and supports both i386 and AMD64/EMT64
architectures. It comes in a 4.7GB live DVD release, a Professional version based on the
stable branch of Portage, and a 700MB CD Mini version. While Sabayon contains
proprietary drivers, free software fans can disable them at boot time.
Sabayon download page
Slackware Linux is the world's oldest surviving Linux distribution.
Slackware download page, BitTorrent trackers
Ubuntu is a popular community-developed Linux distribution for laptops and desktop
machines, and is also gaining popularity on servers. Ubuntu is based on Debian
GNU/Linux, and also serves as the foundation for several other Linux distributions in its