Linux ,by Linus Torvalds ,is an operating system kernel licensed under the GPL and freely distributed.

the official site for the kernel
an unofficial site
an unofficial site


Torvald's git repository


information about the various Linux Distributions
LWN list of Linux Distributions

A rather commercial site operated by the Linux Foundation. Features news, forums, and tutorials.

Software Catalogs


the first version of Linux was released in 1991.

History of Linux ,Ragib Hasan 2002
History of Unix ,Ronda Hauben
Linux History ,Linux Interantional
Arhives some of the first messages by Linus Torvalds regarding Linux
A Brief History of Linux (alternate ) ,Annalee Newitz ,2000-02-08

jcw 2004-05-20: The Register has a delightful article [L1 ] about Linux's origins, and the recent Tocqueville/Brown upheaval. Not in the least for everything Andrew Tanenbaum [L2 ] says, in his fun style.


A variety of commercial entities, including Sun, IBM, SuSE, Red Hat, and others, go through the effort to build the sources, provide maintenance contracts, etc. in an effort to add value to the open source software.

One popular distribution of Linux is SuSE - where one of the Tcl community works to maintain a great Tcl presence in the distribution.


A Linux distribution includes both the Linux kernel and accompanying programs such as a shell and X server, that together make a complete system. Some popular distributions are:

a rolling-release distribution that tries not to tamper with upstream and to stay on the cutting edge (Arch, Manjaro, Antergos)
a fiercely free-software distribution known for militant adherence to its own policies in the quest to maintain a highly-stable and reliable distribution (Debian, Ubuntu, Linux Mint, MX Linux, Elementary, Devuan)
a source-only distribution that lets you compile all packages on your own machine (Gentoo, Calculate)
Puppy Linux
designed to be small
One of the oldest and most "Corporate" distributions (RedHat, CentOS, Fedora)
Known for its stability and for the tight and clean design.
(SUSE, openSUSE)

An intrepid adventurer might also choose to build a Linux system from scratch .


Major features of Linux include:

  • Customizable kernel so that you can build for your machine and hardware needs as well as for specific software needs. This is one reason Linux is popular for routers and dedicated servers as it can be trimmed down easily to meet custom needs.
  • bash, csh, tcsh, ksh, other Unix shells that are the basic UI to the OS.
  • GNU system utilities, many of which are Unix-like or even updated ports of what were originally unix utilities making Linux familiar to the Unix user. The combination of the shells and the GNU utilities are a powerful means of control of your OS.
  • A File System structure that is also very similar to most other Unix OSes.
  • The graphics are on a server/client basis rather than being tied directly into the core system, thus allowing graphical user applications to crash without the OS itself crashing.

Most Linux systems will use either the BSD init style or the SysV init style. init is the 'mother of all processes', both during boot time and during runtime.

There are many distributions of Linux, but the common denominator with them all is that you can build any Linux system into your Linux system. It is the very nature of Linux that you can build to your hardware requirements and your machine needs.

This is also the case with the X Windowing System for creating your desktop to suit your own look/feel choices.

Linux is not Unix. The term Unix has specific legal meaning, and so the origins of the code need to be kept clear.

LES Also note that Linux software is not 100% compatible with Unix and vice-versa. Especially binary things. These often have to compiled for Unix or Linux specifically, probably after some sort of modification.

See Also