Linux (commonly pronounced /?l?n?ks/ LIN-?ks in American English,[4][5] also pronounced /?l?n?ks/ LIN-ooks[6] in Europe) refers to the family of Unix-like computer operating systems using the Linux kernel. Linux can be installed on a wide variety of computer hardware, ranging from mobile phones, tablet computers and video game consoles, to mainframes and supercomputers.[7][8][9][10] Linux is a leading server operating system, and runs the 10 fastest supercomputers in the world.[11]

The development of Linux is one of the most prominent examples of free and open source software collaboration; typically all the underlying source code can be used, freely modified, and redistributed, both commercially and non-commercially, by anyone under licenses such as the GNU General Public License. Typically Linux is packaged in a sell house fast format known as a Linux distribution for desktop and server use. Some popular mainstream Linux distributions include Debian (and its derivatives such as Ubuntu), Fedora and openSUSE. Linux distributions include the Linux kernel and supporting utilities and libraries to fulfill the distribution’s intended use.
A distribution oriented toward desktop use may include the X Window System, the GNOME and KDE Plasma desktop environments. Other 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 any graphical environment from the standard install and instead include other software such as the Apache HTTP Server and a SSH server like OpenSSH. Because Linux is freely redistributable, it is possible for anyone to create a distribution for any intended use. Commonly used applications with desktop Linux systems include the Mozilla Firefox web-browser, the OpenOffice.org office application suite and the GIMP image editor. scholarships for moms
The we buy any house name “Linux” comes from the Linux kernel, originally written in 1991 by Linus Torvalds. The main supporting user space system tools and libraries from the GNU Project (announced in 1983 by Richard Stallman) are the basis for the Free Software Foundation’s preferred name GNU/Linux. hydroxatone reviews
The Unix operating system was conceived and implemented in 1969 at AT&T’s Bell Laboratories in the United States by Ken Thompson, Dennis Ritchie, Douglas McIlroy, and Joe Ossanna. It was first released in 1971 and was initially entirely written in assembly language, a common practice at the time. Later, in a key pioneering approach in 1973, Unix was re-written in the programming language C by Dennis Ritchie (with exceptions to the kernel and I/O). The availability of an operating system written in a high-level language allowed easier portability to different computer platforms. With a legal glitch forcing AT&T to license the operating system’s source code,[clarification needed] Unix quickly grew and became widely adopted by academic institutions and businesses.
The GNU Project, started in 1983 by Richard Stallman, had the goal of creating a “complete Unix-compatible software system” composed entirely of free software. Work began in 1984.[14] Later, in 1985, Stallman started the Free Software Foundation and wrote the GNU General Public License (GNU GPL) in 1989. By the early 1990s, many of the programs required in an operating system (such as libraries, compilers, text editors, a Unix shell, and a windowing system) were completed, although low-level elements such as device drivers, daemons, and the kernel were stalled and incomplete.[15] Linus Torvalds has said that if the GNU kernel had been available at the time (1991), he would not have decided to write his own.[16]
[edit] BSD
Although not released until 1992 due to legal complications, development of 386BSD, from which NetBSD and FreeBSD descended, predated that of Linux. Linus Torvalds has said that if 386BSD had been available at the time, he probably would not have created Linux.[17]
MINIX is an inexpensive minimal Unix-like operating system, designed for education in computer science, written by Andrew S. Tanenbaum. Starting with version 3, MINIX is free and redesigned also for “serious” use.
In 1991 while attending the University of Helsinki, Torvalds, curious about the operating systems [18] and frustrated by the licensing of MINIX limiting it to educational use only (which prevented any commercial use), began to work on his own operating system which eventually became the Linux kernel.
Torvalds began the development of the Linux kernel on MINIX, and applications written for MINIX were also used on Linux. Later Linux matured and it became possible for Linux to be developed under itself.[19] Also GNU applications replaced all MINIX ones, because with code from the GNU system freely available, it was advantageous if this could be used with the fledgling operating system. Code licensed under the GNU GPL can be used in other projects, so long as they also are released under the same or a compatible license. In order to make the Linux available for commercial use, Torvalds initiated a switch from his original license (which prohibited commercial redistribution) to the GNU GPL.[20] Developers worked to integrate GNU components with Linux to make a fully functional and free operating system.[15]
[edit] Commercial and popular uptake
Main article: Linux adoption
Today, Linux distributions are used in every domain, from embedded systems to supercomputers,[21][22] and have secured a place in server installations often using the popular LAMP application stack.[23] Use of Linux distributions in home and enterprise desktops has been growing.[24][25][26][27][28][29][30] They have also gained popularity with various local and national governments. The federal government of Brazil is well known for its support for Linux.[31][32] News of the Russian military creating their own Linux distribution has also surfaced, and has come to fruition as the G.H.ost Project.[33] The Indian state of Kerala has gone to the extent of mandating for all state high schools to run Linux on their computers.[34][35] China uses Linux exclusively as the operating system for its Loongson processor family to achieve technology independence.[36] In Spain some regions have developed their own anything goes diet Linux distributions, which are widely used in education and official institutions, like gnuLinEx in Extremadura and Guadalinex in Andalusia. Portugal is also using its own Linux distribution Caixa Mágica, used in the Magalhães netbook[37] and the e-escola government program.[38] France and Germany have also taken steps towards the adoption of Linux.[39]
Linux distributions have also become popular in the netbook market, with many devices such as the ASUS Eee PC and Acer Aspire One shipping with customized Linux distributions installed.[40]
[edit] Current development
Torvalds continues to direct the development of the kernel. Stallman heads the Free Software Foundation, which in turn supports the GNU components. Finally, individuals and corporations develop third-party non-GNU components. These third-party components comprise a vast body of work and may include both kernel modules and user applications and libraries. Linux vendors and communities combine and distribute the kernel, GNU components, and non-GNU components, with additional package management software in the form of Linux distributions.
[edit] Design
A Linux-based system is a modular Unix-like operating system. It derives much of its basic design from principles established in Unix during the 1970s and 1980s. Such a system uses a monolithic kernel, the Linux kernel, which handles process control, networking, and peripheral and file system access. Device drivers are either integrated directly with the kernel or added as modules loaded while the system is running.
Separate projects that interface with the kernel provide much of the system’s higher-level functionality. The GNU userland is an important part of most Linux-based systems, providing the most common implementation of the C library, a popular shell, and many of the common Unix tools which carry out many basic operating system tasks. The graphical user interface (or GUI) used by most Linux systems is built on top of an implementation of the X Window System.
[edit] User interface
See also: User interface
Users operate a Linux-based system through a command line interface (CLI), a graphical user interface (GUI), or through controls attached to the associated hardware, which is common for embedded systems. For desktop systems, the default mode is usually a graphical user interface, by which the CLI is available through terminal emulator windows or on a separate virtual console. Most low-level Linux components, including the GNU userland, use the CLI exclusively. The CLI is particularly suited for automation of repetitive or delayed tasks, and provides very simple inter-process communication. A graphical terminal emulator program is often used to access the CLI from a Linux desktop. A Linux system typically implements a CLI by a shell, which is also the traditional way of interacting with a Unix system. A Linux distribution specialized for servers may use the CLI as its only interface.
On desktop systems, the most popular user interfaces are the extensive desktop environments KDE Plasma Desktop, GNOME, and Xfce,[41] though a variety of additional user interfaces exist. Most popular user interfaces are based on the X Window System, often simply called “X”. It provides network transparency and permits a graphical application running on one system to be displayed on another where a user may interact with the application.[42]
Other GUIs may be classified as simple X window managers, such as FVWM, Enlightenment, and Window Maker, which provide a minimalist functionality with respect to the desktop environments. A window manager provides a means to control the placement and appearance of individual application windows, and interacts with the X Window System. The desktop environments include window managers as part of their standard installatations (Metacity for GNOME, Kwin for KDE, Xfwm for XFCE as of 2010) although users may choose to use a different window manager if preferred.
The primary difference between Linux and many other popular contemporary operating systems is that the Linux kernel and other components are free and open source software. Linux is not the only such operating system, although it is by far the most widely used.[43] Some free and open source software licenses are based on the principle of copyleft, a kind of reciprocity: any work derived from a copyleft piece of software must also be copyleft itself. The most common free software license, the GNU GPL, is a form of copyleft, and is used for the Linux kernel and many of the components from the GNU project.
Linux based distributions are intended by developers for interoperability with other operating systems and established computing standards. Linux systems adhere to POSIX,[44] SUS,[45] ISO, and ANSI standards where possible, although to date only one Linux distribution has been POSIX.1 certified, Linux-FT.[46]
Free software projects, although developed in a collaborative fashion, are often produced independently of each other. The fact that the software licenses explicitly permit redistribution, however, provides a basis for larger scale projects that collect the software produced by stand-alone projects and make it available all at once in the form of a Linux distribution.
A Linux distribution, commonly called a “distro”, is a project that manages a remote collection of system software and application software packages available for download and installation through a network connection. This allows the user to adapt the operating system to his/her specific needs. Distributions are maintained by individuals, loose-knit teams, volunteer organizations, and commercial entities. A distribution is responsible for the default configuration of the installed Linux kernel, general system security, and more generally integration of the different software packages into a coherent whole. Distributions typically use a package manager such as dpkg, Synaptic, YAST, or Portage to install, remove and update all of a system’s software from one central location.
[edit] Community
See also: Free software community and Linux User Group
A distribution is largely driven by its developer and user communities. Some vendors develop and fund their distributions on a volunteer basis, Debian being a well-known example. Others maintain a community version of their commercial distributions, as Red Hat does with Fedora.
In many cities and regions, local associations known as Linux User Groups (LUGs) seek to promote their preferred distribution and by extension free software. They hold meetings and provide free demonstrations, training, technical support, and operating system installation to new users. Many Internet communities also provide support to Linux users and developers. Most distributions and free software / open source projects have IRC chatrooms or newsgroups. Online forums are another means for support, with notable examples being LinuxQuestions.org and the Gentoo forums. Linux distributions host mailing lists; commonly there will be a specific topic such as usage or development for a given list.
There are several technology websites with a Linux focus. Print magazines on Linux often include cover disks including software or even complete Linux distributions.[47][48]
Although Linux distributions are generally available without charge, several large corporations sell, support, and contribute to the development of the components of the system and of free software. An analysis of the Linux kernel showed 75 percent of the code from December 2008 to January 2010 was developed by programmers working for corporations, leaving about 18 percent to the traditional, open source community.[49] Some of the major corporations that contribute include Dell, IBM, HP, Oracle, Sun Microsystems (now part of Oracle), Novell, and Nokia. A number of corporations, notably Red Hat, have built their entire business around Linux distributions.
The free software licenses, on which the various software packages of a distribution built on the Linux kernel are based, explicitly accommodate and encourage commercialization; the relationship between a Linux distribution as a whole and individual vendors may be seen as symbiotic. One common business model of commercial suppliers is charging for support, especially for business users. A number of companies also offer a specialized business version of their distribution, which adds proprietary support packages and tools to administer higher numbers of installations or to simplify administrative tasks.
Another business model is to give away the software in order to sell hardware. This used to be the norm in the computer industry, with operating systems such as CP/M, Apple DOS and versions of MacOS prior to 7.5 freely copyable (but not modifiable). As computer hardware standardized throughout the 1980s, it became more difficult for hardware manufacturers to employ this tactic, as their OS would run on any computer that shared the same architecture.
[edit] Programming on Linux
Linux distributions support dozens of programming languages. The most common collection of utilities for building both Linux applications and operating system programs is found within the GNU toolchain, which includes the GNU Compiler Collection (GCC) and the GNU build system. Amongst others, GCC provides compilers for Ada, C, C++, Java, and Fortran. Proprietary compilers for Linux include the Intel C++ Compiler, Sun Studio, and IBM XL C/C++ Compiler. BASIC is supported in such forms as Gambas, FreeBASIC, and XBasic.
Most distributions also include support for PHP, Perl, Ruby, Python and other dynamic languages. While not as common, Linux also supports C# (via Mono), Vala, and Scheme. A number of Java Virtual Machines and development kits run on Linux, including the original Sun Microsystems JVM (HotSpot), and IBM’s J2SE RE, as well as many open-source projects like Kaffe.
The two main frameworks for developing graphical applications are those of GNOME and KDE. These projects are based on the GTK+ and Qt widget toolkits, respectively, which can also be used independently of the larger framework. Both support a wide variety of languages. There are a number of Integrated development environments available including Anjuta, Code::Blocks, Eclipse, Geany, ActiveState Komodo, KDevelop, Lazarus, MonoDevelop, NetBeans, Qt Creator and Omnis Studio, while the long-established editors Vim and Emacs remain popular.[50]
[edit] Uses
As well as those designed for general purpose use on desktops and servers, distributions may be specialized for different purposes including: computer architecture support, embedded systems, stability, security, localization to a specific region or language, targeting of specific user groups, support for real-time applications, or commitment to a given desktop environment. Furthermore, some distributions deliberately include only free software. Currently, over three hundred distributions are actively developed, with about a dozen distributions being most popular for general-purpose use.[51]
Linux is a widely ported operating system kernel. The Linux kernel runs on a highly diverse range of computer architectures: in the hand-held ARM-based iPAQ and the mainframe IBM System z9, System z10 in devices ranging from mobile phones to supercomputers.[52] Specialized distributions exist for less mainstream architectures. The ELKS kernel fork can run on Intel 8086 or Intel 80286 16-bit microprocessors, while the µClinux kernel fork may run on systems without a memory management unit. The kernel also runs on architectures that were only ever intended to use a manufacturer-created operating system, such as Macintosh computers (with both PowerPC and Intel processors), PDAs, video game consoles, portable music players, and mobile phones.
There are several industry associations and hardware conferences devoted to maintaining and improving support for diverse hardware under Linux, such as FreedomHEC.
[edit] Desktop
Main article: Desktop Linux
The popularity of Linux on standard desktop computers (and laptops) has been increasing over the years.[53] Currently most distributions include a graphical user environment. The two most popular such environments are GNOME and KDE Plasma Desktop, both of which are mature and support a wide variety of languages.
The performance of Linux on the desktop has been a controversial topic; for example in 2007 Con Kolivas accused the Linux community of favoring performance on servers. He quit Linux kernel development because he was frustrated with this lack of focus on the desktop, and then gave a “tell all” interview on the topic.[54] Since then a significant amount of development has been undertaken in an effort to improve the desktop experience. Projects such as upstart aim for a faster boot time.[55] There are several companies that have ported their own or other companies’ games to Linux.
Many types of applications available for Microsoft Windows and Mac OS X are also available for Linux. Commonly, either a free software application will exist which does the functions of an application found on another operating system, or that application will have a version that works on Linux (such as Skype). Furthermore, the Wine project provides a Windows compatibility layer to run unmodified Windows applications on Linux. CrossOver is a proprietary solution based on the open source Wine project that supports running Windows versions of Microsoft Office, Intuit applications such as Quicken and QuickBooks, Adobe Photoshop versions through CS2, and many popular games such as World of Warcraft and Team Fortress 2. In other cases, where there is no Linux port of some software in areas such as desktop publishing[56] and professional audio,[57][58][59] there is equivalent software available on Linux.
Many popular applications are available for a wide variety of operating systems. For example Mozilla Firefox, and OpenOffice.org have downloadable versions for all major operating systems. Furthermore, some applications were initially developed for Linux (such as Pidgin, and GIMP) and, due to their popularity, were ported to other operating systems (including Windows and Mac OS X).
A growing number of proprietary desktop applications are also supported on Linux;[60] see List of proprietary software for Linux. In the field of animation and visual effects, most high end software, such as AutoDesk Maya, Softimage XSI and Apple Shake, is available for Linux, Windows and/or Mac OS X.
The collaborative nature of free software development allows distributed teams to perform language localization of some Linux distributions for use in locales where localizing proprietary systems would not be cost-effective. For example the Sinhalese language version of the Knoppix distribution was available significantly before Microsoft Windows XP was translated to Sinhalese.[citation needed] In this case the Lanka Linux User Group played a major part in developing the localized system by combining the knowledge of university professors, linguists, and local developers.
Installing, updating and removing software in Linux is typically done through the use of package managers such as Synaptic Package Manager, PackageKit, and Yum Extender. While major Linux distributions have extensive repositories (tens of thousands of packages), not all the software that can run on Linux is available from the official repositories. Alternatively, users can install packages from unofficial repositories, download pre-compiled packages directly from websites, or compile the source code by themselves. All these methods come with different degrees of difficulty, compiling the source code is in general considered a challenging process for new Linux users, but it’s hardly needed in modern distributions.