Linux

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds.

The Linux family of operating systems is based on this kernel and deployed on both traditional computer systems such as personal computers and servers, usually in the form of Linux distributions, and on various embedded devices such as routers, wireless access points, PBXes, set-top boxes, FTA receivers, smart TVs, PVRs, and NAS appliances.

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds.

Linus Benedict Torvalds (, ; born December 28, 1969) is a Finnish-American software engineer who is the creator and, historically, the principal developer of the Linux kernel, which is the kernel for Linux operating systems (distributions) and other operating systems such as Android and Chrome OS.

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds.

Free and open-source operating systems such as Linux and descendants of BSD are widely utilized today, powering millions of servers, desktops, smartphones (e.g. Android), and other devices.

Distributions intended for servers may omit graphics altogether, or include a solution stack such as LAMP.

LAMP (Linux, Apache, MySQL, PHP/Perl/Python) is an archetypal model of web service stacks, named as an acronym of the names of its original four open-source components: the Linux operating system, the Apache HTTP Server, the MySQL relational database management system (RDBMS), and the PHP programming language.

Linux is the leading operating system on servers and other big iron systems such as mainframe computers, and the only OS used on TOP500 supercomputers (since November 2017, having gradually eliminated all competitors).

Since November 2017, all of the world's fastest 500 supercomputers run Linux-based operating systems.

Desktop Linux distributions include a windowing system such as X11 or Wayland, and a desktop environment such as GNOME or KDE Plasma.

Wayland is developed by a group of volunteers initially led by Kristian Høgsberg as a free and open-source community-driven project with the aim of replacing the X Window System with a modern, secure, simpler windowing system in Linux and other Unix-like operating systems.

Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

The combination of GNU and Linux has become ubiquitous to the point that the duo is often referred to as just "Linux" in short, or, less frequently, GNU/Linux.

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds.

macOS by Apple Inc. is in second place (13.23%), and the varieties of Linux are collectively in third place (1.57%).

Linux is the leading operating system on servers and other big iron systems such as mainframe computers, and the only OS used on TOP500 supercomputers (since November 2017, having gradually eliminated all competitors).

In addition, mainframes are more secure than other computer types: the NIST vulnerabilities database, US-CERT, rates traditional mainframes such as IBM Z (previously called z Systems, System z and zSeries), Unisys Dorado and Unisys Libra as among the most secure with vulnerabilities in the low single digits as compared with thousands for Windows, UNIX, and Linux.

Although not released until 1992, due to legal complications, development of 386BSD, from which NetBSD, OpenBSD and FreeBSD descended, predated that of Linux.

FreeBSD has similarities with Linux, with two major differences in scope and licensing: FreeBSD maintains a complete system, i.e. the project delivers a kernel, device drivers, userland utilities, and documentation, as opposed to Linux only delivering a kernel and drivers, and relying on third-parties for system software; and FreeBSD source code is generally released under a permissive BSD license, as opposed to the copyleft GPL used by Linux.

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds.

Some add a wildcard character to the name to make an abbreviation like "Un*x" or "*nix", since Unix-like systems often have Unix-like names such as AIX, A/UX, HP-UX, IRIX, Linux, Minix, Ultrix, Xenix, Xinu, and XNU.

Distributions intended for servers may omit graphics altogether, or include a solution stack such as LAMP.

Linux was originally developed for personal computers based on the Intel x86 architecture, but has since been ported to more platforms than any other operating system.

In that same market, the choice of operating systems has effectively been reduced to three: Microsoft Windows, macOS, and Linux.

The source code 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 Linux Information Project defines source code as:

The Project's implementation of the C library functions as a wrapper for the system calls of the Linux kernel necessary to the kernel-userspace interface, the toolchain is a broad collection of programming tools vital to Linux development (including the compilers used to build the Linux kernel itself), and the coreutils implement many basic Unix tools.

GCC is a key component of the GNU toolchain and the standard compiler for most projects related to GNU and Linux, including the Linux kernel.

Projects such as Upstart and systemd aim for a faster boot time; the Wayland and Mir projects aim at replacing X11 while enhancing desktop performance, security and appearance.

The systemd software suite provides fundamental building blocks for a Linux operating system.

Linux was originally developed for personal computers based on the Intel x86 architecture, but has since been ported to more platforms than any other operating system.

Although not released until 1992, due to legal complications, development of 386BSD, from which NetBSD, OpenBSD and FreeBSD descended, predated that of Linux.

In comparison, Linux device driver code often must be reworked for each new architecture.

Many smartphones and tablet computers run Android and other Linux derivatives.

Android is a Linux-based operating system that Google offers as open source under the Apache license.

The Project's implementation of the C library functions as a wrapper for the system calls of the Linux kernel necessary to the kernel-userspace interface, the toolchain is a broad collection of programming tools vital to Linux development (including the compilers used to build the Linux kernel itself), and the coreutils implement many basic Unix tools.

The GNU C Library project provides the core libraries for the GNU system and GNU/Linux systems, as well as many other systems that use Linux as the kernel.

Linux is the leading operating system on servers and other big iron systems such as mainframe computers, and the only OS used on TOP500 supercomputers (since November 2017, having gradually eliminated all competitors).

All the fastest supercomputers in the decade since the Earth Simulator supercomputer have used operating systems based on Linux.

Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project.

The operating system (prominent examples being Microsoft Windows, macOS, Linux, and z/OS), allows the parts of a computer to work together by performing tasks like transferring data between memory and disks or rendering output onto a display device.

Adoption of Linux in production environments, rather than being used only by hobbyists, started to take off first in the mid-1990s in the supercomputing community, where organizations such as NASA started to replace their increasingly expensive machines with clusters of inexpensive commodity computers running Linux.

The developers used Linux, the Parallel Virtual Machine toolkit and the Message Passing Interface library to achieve high performance at a relatively low cost.

Linux distributions have also become popular in the netbook market, with many devices shipping with customized Linux distributions installed, and Google releasing their own Chrome OS designed for netbooks.

The 6" Libretto 20 dates back to early 1996 and weighed only 840g. Apple also had a line of PowerBook Duos that were ultra-portable Macintosh laptops in the mid 90s. More recently, Psion's now-discontinued netBook line, the OLPC XO-1 (initially called US$100 laptop) and the Palm Foleo were all small, portable, network-enabled computers. The generic use of the term "netbook", however, began in 2007 when Asus unveiled the Asus Eee PC. Originally designed for emerging markets, the 23 x device weighed about 0.9 kg and featured a 7 in display, a keyboard approximately 85% the size of a normal keyboard, a solid-state drive and a custom version of Linux with a simplified user interface geared towards netbook use. Following the Eee PC, Everex launched its Linux-based CloudBook; Windows XP and Windows Vista models were also introduced and MSI released the Wind—others soon followed suit.

Desktop Linux distributions include a windowing system such as X11 or Wayland, and a desktop environment such as GNOME or KDE Plasma.

When compared with the X-based desktop environments available for Unix-like operating systems such as Linux and FreeBSD, the proprietary desktop environments included with Windows and macOS have relatively fixed layouts and static features, with highly integrated "seamless" designs that aim to provide mostly consistent customer experiences across installations.