About Linux

What is Linux?

A multitasking, multi-user operating system Informally refers to the operating system as well as the standard tools and applications distributed with it.
Specifically, Linux refers to the kernel which forms the core of the operating system The kernel is distributed with indispensable utilities and applications, such as compilers, editors, command interpreters, etc.
Most Linux software distributed under the GNU general public license (GPL)
 

What are Linux Systems Used For?

Linux is based on Unix operating systems, traditionally associated with heavy computing, stability and backend services, computationally intensive tasks such as visualisation and graphics rendering,scientific computation and simulations academic laboratories.
Large portion of the Internet is Unix-based, Linux is revolutionising the old legacy of Unix by bringing the operating system to desktops and everyday users.

Since Linux is a multiuser operating system, users must authenticate themselves before gaining access.

Authentication is done with a username and password, configured by the system administrator.

Although visually different, the process of logging in the same in both text and graphical mode.

The combination of username, password and disk space for personal files is called a user account

Note : that Linux is case-sensitive


What are Linux Systems Used For?

Linux systems often used for back end services: Web servers, database servers, file servers, mail servers, ftp servers,firewalls, routers, print servers...
Linux is slowly moving onto the desktop: Desktop, office suites, graphics manipulation
Growing commercial interest in Linux-based computing: Reliable, secure IT systems Cost-effective solutions
Support from traditional Unix companies such as Sun, HP, IBM,Novell

History

Linux began in 1980's as an effort to create a free Unix-like operating system.

The project was called GNU and was run by the Free Software Foundation (FSF) created by Richard Stallman Development began with system tools such as editors, a compiler and hundreds of other utilities By early 1990's most of the components were written, but the operating system was missing a kernel Coincidentally, Linus Torvalds of Helsinki University had been working on a Unix-based kernel – the first version was completed in 1994.

Linus liked the endeavours of the Free Software Foundation and released his kernel under the GNU GPL.

The Linux kernel and GNU tools made a complete, free operating system: the GNU/Linux operating system.

Open Source Licenses

GPL was one of the most important contributions of the FSF

The Open Source definition (http://www.opensource.org) is

based on the GPL.

Open Source licenses ensure basic freedoms, including:

The freedom to use the software for any purpose,

The freedom to distribute the software to others;

The freedom to modify the software;

The freedom to distribute the modified software to others (under the

same licensing conditions) GPL, MPL and BSD licenses are some examples.