Linux ( or ) is a family of open-source

Unix-like A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also i ...

s based on the Linux kernel, an

operating system kernel The kernel is a computer program at the core of a computer's operating system and generally has complete control over everything in the system. It is the portion of the operating system code that is always resident in memory and facilitates in ...

first released on September 17, 1991, by

Linus Torvalds Linus Benedict Torvalds ( , ; born 28 December 1969) is a Finnish software engineer who is the creator and, historically, the lead developer of the Linux kernel, used by Linux distributions and other operating systems such as Android. He also ...

. Linux is typically packaged as a Linux distribution, which includes the kernel and supporting

system software System software is software designed to provide a platform for other software. Examples of system software include operating systems (OS) like macOS, Linux, Android and Microsoft Windows, computational science software, game engines, search engin ...

and

libraries A library is a collection of Document, materials, books or media that are accessible for use and not just for display purposes. A library provides physical (hard copies) or electronic media, digital access (soft copies) materials, and may be a ...

, many of which are provided by the

GNU Project The GNU Project () is a free software, mass collaboration project announced by Richard Stallman on September 27, 1983. Its goal is to give computer users freedom and control in their use of their computers and computing devices by collaborat ...

. Many Linux distributions use the word "Linux" in their name, but the

Free Software Foundation The Free Software Foundation (FSF) is a 501(c)(3) non-profit organization founded by Richard Stallman on October 4, 1985, to support the free software movement, with the organization's preference for software being distributed under copyleft (" ...

uses the name "GNU/Linux" to emphasize the importance of

GNU GNU () is an extensive collection of free software (383 packages as of January 2022), which can be used as an operating system or can be used in parts with other operating systems. The use of the completed GNU tools led to the family of operat ...

software, causing some controversy. Popular Linux distributions include Debian,

Fedora Linux Fedora Linux is a Linux distribution developed by the Fedora Project. Fedora contains software distributed under various free and open-source licenses and aims to be on the leading edge of open-source technologies. Fedora is the upstream source ...

, and

Ubuntu Ubuntu ( ) is a Linux distribution based on Debian and composed mostly of free and open-source software. Ubuntu is officially released in three editions: '' Desktop'', ''Server'', and ''Core'' for Internet of things devices and robots. All ...

, the latter of which itself consists of many different distributions and modifications, including

Lubuntu Lubuntu ( ) is a lightweight Linux distribution based on Ubuntu and uses the LXQt desktop environment in place of Ubuntu's GNOME desktop. Lubuntu was originally touted as being "lighter, less resource hungry and more energy-efficient", but now ...

and

Xubuntu Xubuntu () is a Canonical Ltd.–recognized, community-maintained derivative of the Ubuntu operating system. The name ''Xubuntu'' is a portmanteau of ''Xfce'' and ''Ubuntu'', as it uses the Xfce desktop environment, instead of Ubuntu's Unity a ...

. Commercial distributions include

Red Hat Enterprise Linux Red Hat Enterprise Linux (RHEL) is a commercial open-source Linux distribution developed by Red Hat for the commercial market. Red Hat Enterprise Linux is released in server versions for x86-64, Power ISA, ARM64, and IBM Z and a desktop ...

and SUSE Linux Enterprise. Desktop Linux distributions include a

windowing system In computing, a windowing system (or window system) is software that manages separately different parts of display screens. It is a type of graphical user interface (GUI) which implements the WIMP (windows, icons, menus, pointer) paradigm fo ...

such as

X11 The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X provides the basic framework for a GUI environment: drawing and moving windows on the display device and interacting wi ...

or Wayland, and a

desktop environment In computing, a desktop environment (DE) is an implementation of the desktop metaphor made of a bundle of programs running on top of a computer operating system that share a common graphical user interface (GUI), sometimes described as a graphica ...

such as GNOME or KDE Plasma. Distributions intended for servers may omit graphics altogether, or include a

solution stack In computing, a solution stack or software stack is a set of software subsystems or components needed to create a complete platform such that no additional software is needed to support applications. Applications are said to "run on" or "run on t ...

such as

LAMP Lamp, Lamps or LAMP may refer to: Lighting * Oil lamp, using an oil-based fuel source * Kerosene lamp, using kerosene as a fuel * Electric lamp, or light bulb, a replaceable component that produces light from electricity * Light fixture, or li ...

. Because Linux is freely redistributable, anyone may create a distribution for any purpose. Linux was originally developed for

personal computer A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tec ...

s based on the

Intel x86 x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was intr ...

architecture, but has since been

ported In software engineering, porting is the process of adapting software for the purpose of achieving some form of execution in a computing environment that is different from the one that a given program (meant for such execution) was originally desi ...

to more platforms than any other operating system. Because of the dominance of the Linux-based Android on

smartphone A smartphone is a portable computer device that combines mobile telephone and computing functions into one unit. They are distinguished from feature phones by their stronger hardware capabilities and extensive mobile operating systems, whic ...

s, Linux, including Android, has the

largest Large means of great size. Large may also refer to: Mathematics * Arbitrarily large, a phrase in mathematics * Large cardinal, a property of certain transfinite numbers * Large category, a category with a proper class of objects and morphisms (o ...

installed base Installed base (also install base, install duser base or just user base) is a measure of the number of units of a product or service that are actually in use, as opposed to market share, which only reflects sales over a particular period. Alth ...

of all

general-purpose operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

s, . Although Linux is, , used by only around 2.6 percent of desktop computers, the

Chromebook A Chromebook (sometimes stylized in lowercase as chromebook) is a laptop or tablet running the Linux-based ChromeOS as its operating system. Initially designed to heavily rely on web applications for tasks using the Google Chrome browser, Chrome ...

, which runs the Linux kernel-based

ChromeOS ChromeOS, sometimes stylized as chromeOS and formerly styled as Chrome OS, is a Linux-based operating system designed by Google. It is derived from the open-source ChromiumOS and uses the Google Chrome web browser as its principal user interfa ...

, dominates the US

K–12 K–12, from kindergarten to 12th grade, is an American English expression that indicates the range of years of publicly supported primary and secondary education found in the United States, which is similar to publicly supported school grades ...

education market and represents nearly 20 percent of sub-$300 notebook sales in the US. Linux is the leading operating system on servers (over 96.4% of the top 1 million web servers' operating systems are Linux), leads other

big iron "Big Iron" is a country ballad written and performed by Marty Robbins, originally released as an album track on ''Gunfighter Ballads and Trail Songs'' in September 1959, then as a single in February 1960 with the song "Saddle Tramp" as the B-si ...

systems such as mainframe computers, and is used on all of the world's 500 fastest supercompters (since November 2017, having gradually displaced all competitors). Linux also runs on

embedded system An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is ''embedded'' ...

s, i.e. devices whose operating system is typically built into the firmware and is highly tailored to the system. This includes routers,

automation Automation describes a wide range of technologies that reduce human intervention in processes, namely by predetermining decision criteria, subprocess relationships, and related actions, as well as embodying those predeterminations in machines ...

controls, smart home devices,

video game console A video game console is an electronic device that outputs a video signal or image to display a video game that can be played with a game controller. These may be home consoles, which are generally placed in a permanent location connected to ...

television Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertisin ...

s (Samsung and LG

Smart TV A smart TV, also known as a connected TV (CTV), is a traditional television set with integrated Internet and interactive Web 2.0 features, which allows users to stream music and videos, browse the internet, and view photos. Smart TVs are a techn ...

s), automobiles (Tesla, Audi, Mercedes-Benz, Hyundai and Toyota), and

spacecraft A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, p ...

(

Falcon 9 Falcon 9 is a partially reusable medium lift launch vehicle that can carry cargo and crew into Earth orbit, produced by American aerospace company SpaceX. The rocket has two stages. The first (booster) stage carries the second stage and pay ...

rocket, Dragon crew capsule and the ''Perseverance'' rover). Linux is one of the most prominent examples of free and open-source

software Software is a set of computer programs and associated software documentation, documentation and data (computing), data. This is in contrast to Computer hardware, hardware, from which the system is built and which actually performs the work. ...

collaboration. The

source code In computing, source code, or simply code, is any collection of code, with or without comments, written using a human-readable programming language, usually as plain text. The source code of a program is specially designed to facilitate the w ...

may be used, modified and distributed commercially or non-commercially by anyone under the terms of its respective licenses, such as the

GNU General Public License The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general ...

(GPL). The Linux kernel, for example, is licensed under the GPLv2.

History

Precursors

The

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, an ...

operating system was conceived and implemented in 1969, at

AT&T AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile te ...

Bell Labs Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial Research and development, research and scientific developm ...

, in the United States by

Ken Thompson Kenneth Lane Thompson (born February 4, 1943) is an American pioneer of computer science. Thompson worked at Bell Labs for most of his career where he designed and implemented the original Unix operating system. He also invented the B programmi ...

, Dennis Ritchie,

Douglas McIlroy Malcolm Douglas McIlroy (born 1932) is a mathematician, engineer, and programmer. As of 2019 he is an Adjunct Professor of Computer Science at Dartmouth College. McIlroy is best known for having originally proposed Unix pipelines and developed se ...

, and

Joe Ossanna Joseph Frank Ossanna, Jr. (December 10, 1928 – November 28, 1977) was an electrical engineer and computer programmer who worked as a member of the technical staff at the Bell Telephone Laboratories in Murray Hill, New Jersey. He became active ...

. First released in 1971, Unix was written entirely in assembly language, as was common practice at the time. In 1973, in a key pioneering approach, it was rewritten in the C programming language by Dennis Ritchie (with the exception of some hardware and I/O routines). The availability of a

high-level language In computer science, a high-level programming language is a programming language with strong abstraction from the details of the computer. In contrast to low-level programming languages, it may use natural language ''elements'', be easier to use, ...

implementation of Unix made its

porting In software engineering, porting is the process of adapting software for the purpose of achieving some form of execution in a computing environment that is different from the one that a given program (meant for such execution) was originally desi ...

to different computer platforms easier. Due to an earlier

antitrust case In the United States, antitrust law is a collection of mostly federal laws that regulate the conduct and organization of businesses to promote competition and prevent unjustified monopolies. The three main U.S. antitrust statutes are the Sherman ...

forbidding it from entering the computer business, AT&T licensed the operating system's source code as a trade secret to anyone who asked. As a result, Unix grew quickly and became widely adopted by academic institutions and businesses. In 1984, AT&T divested itself of its regional operating companies, and was released from its obligation not to enter the computer business; freed of that obligation, Bell Labs began selling Unix as a

proprietary {{Short pages monitor LinuxWasch3

In the United States, the name ''Linux'' is a trademark registered to Linus Torvalds. Initially, nobody registered it, but on August 15, 1994, William R. Della Croce, Jr. filed for the trademark ''Linux'', and then demanded royalties from Linux distributors. In 1996, Torvalds and some affected organizations sued him to have the trademark assigned to Torvalds, and, in 1997, the case was settled. The licensing of the trademark has since been handled by the

Linux Mark Institute The Linux Mark Institute (LMI, fully "LMI Oregon, LLC") is an organization which administers the "''Linux''" trademark on behalf of Linus Torvalds for computer software which includes the Linux kernel, computer hardware utilizing Linux-based sof ...

(LMI). Torvalds has stated that he trademarked the name only to prevent someone else from using it. LMI originally charged a nominal sublicensing fee for use of the Linux name as part of trademarks, but later changed this in favor of offering a free, perpetual worldwide sublicense. The

(FSF) prefers ''GNU/Linux'' as the name when referring to the operating system as a whole, because it considers Linux distributions to be

variants Variant may refer to: In arts and entertainment * ''Variant'' (magazine), a former British cultural magazine * Variant cover, an issue of comic books with varying cover art * ''Variant'' (novel), a novel by Robison Wells * "The Variant", 2021 e ...

of the

operating system initiated in 1983 by

Richard Stallman Richard Matthew Stallman (; born March 16, 1953), also known by his initials, rms, is an American free software movement activist and programmer. He campaigns for software to be distributed in such a manner that its users have the freedom to ...

, president of the FSF. They explicitly take no issue over the name Android for the Android OS, which is also an operating system based on the Linux kernel, as GNU is not a part of it. A minority of public figures and software projects other than Stallman and the FSF, notably Debian (which had been sponsored by the FSF up to 1996), also use ''GNU/Linux'' when referring to the operating system as a whole. Most media and common usage, however, refers to this family of operating systems simply as ''Linux'', as do many large Linux distributions (for example, SUSE Linux and

). By contrast, Linux distributions containing only free software use "GNU/Linux" or simply "GNU", such as Trisquel GNU/Linux,

Parabola GNU/Linux-libre Parabola GNU/Linux-libre is an operating system for the i686, x86-64 and ARMv7 architectures. It is based on many of the packages from Arch Linux and Arch Linux ARM, but distinguishes from the former by offering only free software. It includes th ...

, BLAG Linux and GNU, and

gNewSense gNewSense was a Linux distribution, active from 2006 to 2016. It was based on Debian, and developed with sponsorship from the Free Software Foundation. Its goal was user-friendliness, but with all proprietary (e.g. binary blobs) and non-free ...

. , about 8% to 13% of the

lines of code Source lines of code (SLOC), also known as lines of code (LOC), is a software metric used to measure the size of a computer program by counting the number of lines in the text of the program's source code. SLOC is typically used to predict the am ...

of the Linux distribution Ubuntu (version "Natty") is made of GNU components (the range depending on whether GNOME is considered part of GNU); meanwhile, 6% is taken by the Linux kernel, increased to 9% when including its direct dependencies. (

self-published Self-publishing is the publication of media by its author at their own cost, without the involvement of a publisher. The term usually refers to written media, such as books and magazines, either as an ebook or as a physical copy using POD (pri ...

data)

Notes

References

External links

*
Graphical map of Linux Internals

Linux kernel website and archives

The History of Linux in GIT Repository Format 1992–2010
{{Authority control 1991 software Computing platforms Cross-platform software Finnish inventions Free software programmed in C Linus Torvalds Operating systems Unix variants

History

Precursors

See also

Notes

References

External links