Photo:1
Photo:2
Photo:3
Photo:4
Photo:1 Photo:2 Photo:3 Photo:4 |
| Unix | |
| 3>
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 to anyone who asked,[22] Unix quickly grew and became widely adopted by academic institutions and businesses. In 1984, AT&T divested itself of Bell Labs. Free of the legal glitch requiring free licensing, Bell Labs began selling Unix as a proprietary product.
Richard Stallman, founder of the GNU project
Tags:Language,Kernel,License,/,Operating System,Source Code,Gnu Project,Richard Stallman,Unix,At&t,United States,Ken Thompson,Dennis Ritchie,Douglas Mcilroy,Joe Ossanna,Assembly Language,C,Portability,Proprietary,Free, | |
| GNU | |
| 3>
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.[23] 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.[24] 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.[25]
Tags:Linus Torvalds,Libraries,Free Software Foundation,Free Software,Gnu General Public License,Compilers,Text Editors,Unix Shell,Device Drivers,Daemons,Gnu Kernel,Shell,Gnu Gpl, | |
| BSD | |
| 3>
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.[26]
Tags:386bsd,Netbsd, | |
| MINIX | |
| 3>
Andrew S. Tanenbaum (left), author of the MINIX operating system, and Linus Torvalds (right), principal author of the Linux kernel
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 was free and redesigned for “serious” use.
In 1991 while attending the University of Helsinki, Torvalds became curious about the operating systems [27] and frustrated by the licensing of MINIX, which limited it to educational use only and prevented any commercial use. He 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 further Linux development took place on Linux systems.[28] GNU applications also replaced all MINIX components, because it was advantageous to use the freely available code from the GNU project with the fledgling operating system. (Code licensed under the GNU GPL can be reused in other projects as long as they also are released under the same or a compatible license.) In order to make Linux available for commercial use, Torvalds initiated a switch from his original license, which prohibited commercial redistribution, to the GNU GPL.[29] Developers worked to integrate GNU components with Linux to make a fully functional and free operating system.[24]
Tags:Developer,Unix-like,Andrew S. Tanenbaum,Minix,Version 3, Minix,University Of Helsinki, | |
| Commercial and popular uptake | |
| 3>
Ubuntu, a popular Linux distribution
Main article: Linux adoption
Today, Linux distributions are used in every domain, from embedded systems to supercomputers,[30][15] and have secured a place in server installations often using the popular LAMP application stack.[31] Use of Linux distributions in home and enterprise desktops has been growing.[32][33][34][35][36][37][38] They have also gained popularity with various local and national governments. The federal government of Brazil is well known for its support for Linux.[39][40] News of the Russian military creating its own Linux distribution has also surfaced, and has come to fruition as the G.H.ost Project.[41] The Indian state of Kerala has gone to the extent of mandating that all state high schools run Linux on their computers.[42][43] China uses Linux exclusively as the operating system for its Loongson processor family to achieve technology independence.[44] In Spain some regions have developed their own 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[45] and the e-escola government program.[46] France and Germany have also taken steps toward the adoption of Linux.[47]
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.[48]
Tags:Embedded Systems,Ubuntu,Supercomputers,Server,Lamp,Loongson,Gnulinex,Extremadura,Guadalinex,Andalusia,Caixa Mágica,France,Netbook,Asus Eee Pc,Sus,Ada, | |
| Current development | |
| 3>
Torvalds continues to direct the development of the kernel.[49] Stallman heads the Free Software Foundation,[50] which in turn supports the GNU components.[51] 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.
Tags: | |
| Design | |
| 2>
This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (August 2011)
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.
Tags:Monolithic,Userland,User Interface,X Window System,Cite,References Or Sources,Reliable Sources,Challenged,Monolithic Kernel,Peripheral,File System,C Library,Unix Tools,Graphical User Interface, | |
| User interface | |
| 3>
This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (August 2011)
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,[52] 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.[53]
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 installations (Mutter for GNOME, Kwin for KDE, Xfwm for Xfce as of January 2012) although users may choose to use a different window manager if preferred.
Tags:Servers,Desktop Environment,Gnome,Kde Plasma,Xfce,Command Line Interface,Terminal Emulator,Inter-process Communication,Desktop Environments,Kde Plasma Desktop,Network Transparency,X Window Managers,Fvwm,Enlightenment,Window Maker,Minimalist,Mutter,Kwin,Xfwm, | |
| Development | |
| 2>
Simplified history of Unix-like operating systems. Linux shares similar architecture and concepts (as part of the POSIX standard) but does not share non-free source code with the original Unix or MINIX.
Main article: Linux distribution
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.[54] 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,[55] SUS,[56] ISO, and ANSI standards where possible, although to date only one Linux distribution has been POSIX.1 certified, Linux-FT.[57][58]
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 users to adapt the operating system to their 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.
Tags:Free And Open Source Software,Posix,Open Source, | |
| Community | |
| 3>
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 and Novell does with openSUSE.
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 various distribution specific support and community forums, such as ones for Ubuntu, Fedora, and Gentoo. 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.[59][60]
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.[61] 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 and Novell, have built a significant 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 Mac OS prior to 7.5 freely copyable (but not modifiable). As computer hardware standardized throughout the 1980s, it became more difficult for hardware manufacturers to profit from this tactic, as the OS would run on any manufacturer's computer that shared the same architecture.
Tags:Computer Hardware,Debian,Fedora, | |
| Programming on Linux | |
| 3>
Most Linux distributions support dozens of programming languages. The original development tools used for building both Linux applications and operating system programs are 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. First released in 2003, the Low Level Virtual Machine project provides an alternative open-source compiler for many languages. Proprietary compilers for Linux include the Intel C++ Compiler, Sun Studio, and IBM XL C/C++ Compiler. BASIC in the form of Visual 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 and JikesRVM.
GNOME and KDE are popular desktop environments and provide a framework for developing applications. 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, CodeLite, Eclipse, Geany, ActiveState Komodo, KDevelop, Lazarus, MonoDevelop, NetBeans, Qt Creator and Omnis Studio, while the long-established editors Vim and Emacs remain popular.[62]
Tags:Programming Languages,Ported, | |
| Uses | |
| 2>
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.[63]
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.[64] 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.
Tags:Arm,Powerpc,Operating System Kernel,Mobile Phones,Video Game Consoles, | |
| Desktop | |
| 3>
Main article: Desktop Linux
The popularity of Linux on standard desktop computers and laptops has been increasing over the years.[65] Currently most distributions include a graphical user environment, with the two most popular environments being GNOME (which can utilize additional shells such as the default GNOME Shell and Ubuntu Unity), and the KDE Plasma Desktop.
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.[66] Since then a significant amount of development has been undertaken in an effort to improve the desktop experience. Projects such as Upstart and systemd aim for a faster boot time.
Tags: | |
zote monety |