Linux pdf (2014) CasTaN

Linux (Listeni/ˈlɪnəks/ LIN-uks or, less frequently used, /ˈlaɪnəks/ LYN-uks) is a Unix-like and
mostly POSIX-compliant computer operating system assembled under the model of free and open-source
software development and distribution. The defining component of Linux is the Linux kernel, an
operating system kernel first released on 5 October 1991 by Linus Torvalds. The Free Software
Foundation uses the name GNU/Linux to describe the operating system, which has led to some
controversy.

Linux was originally developed as a free operating system for Intel x86–based personal computers,
but has since been ported to more computer hardware platforms than any other operating system.
It is the leading operating system on servers and other big iron systems such as mainframe
computers and supercomputers, but is used on only around 1% of desktop computers. Linux also runs
on embedded systems, which are devices whose operating system is typically built into the firmware
and is highly tailored to the system; this includes mobile phones, tablet computers, network
routers, facility automation controls, televisions and video game consoles. Android, the most
widely used operating system for tablets and smartphones, is built on top of the Linux kernel.
The development of Linux is one of the most prominent examples of free and open-source software
collaboration. The underlying source code may be used, modified, and distributed—commercially or
non-commercially—by anyone under licenses such as the GNU General Public License. Typically, Linux
is packaged in a form known as Linux distribution, for both desktop and server use. Some popular
mainstream Linux distributions include Debian, Ubuntu, Linux Mint, Fedora, openSUSE, Arch Linux,
and the commercial Red Hat Enterprise Linux and SUSE Linux Enterprise Server. Linux distributions
include the Linux kernel, supporting utilities and libraries and usually a large amount of
application software to fulfill the distribution's intended use.

A distribution oriented toward desktop use will typically include X11, Wayland or Mir as the
windowing system, and an accompanying desktop environment such as GNOME or the KDE Software
Compilation. Some such distributions may include a less resource intensive desktop such as LXDE or
Xfce, for use on older or less powerful computers. A distribution intended to run as a server may
omit all graphical environments from the standard install, and instead include other software to
set up and operate a solution stack such as LAMP. Because Linux is freely redistributable, anyone
may create a distribution for any intended use.