|
Tux, the penguin, mascot of the Linux kernel |
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| OS family: | Unix-like |
| Latest stable release: | 2.6.22.1 (Linux kernel) / July 10, 2007 |
| Kernel type: | Monolithic kernel |
| License: | Kernel: GNU General Public License/various |
| Working state: | Current |
| Linux |
| History |
| GNU Project • Linux kernel (history • portability and supported architectures) • Naming controversy • Windows and Linux • Adoption • Linus's Law • Tux • SCO and Linux |
| Distribution |
| Linux distribution (list • comparison) • Linux package formats • LiveDistro (list • comparison) • Live USB • Mini Linux |
| Applications |
| Server • Desktop • Embedded • Gaming • Thin client |
Linux (IPA pronunciation: /ˈlɪnʊks/) is a Unix-like computer operating system. Linux is one of the most prominent examples of free software and open source development; its underlying source code can be freely modified, used, and redistributed by anyone.[1]
The Linux kernel was first released to the public on 17 September 1991, for the Intel x86 PC architecture. The kernel was augmented with system utilities and libraries from the GNU project to create a usable operating system, which later led to the alternate term GNU/Linux.[2] Linux is now packaged for different uses in Linux distributions, which contain the sometimes modified kernel along with a variety of other software packages tailored to different requirements.
Predominantly known for its use in servers, Linux has gained the support of corporations such as IBM[3], Sun Microsystems[4], Dell[5], Hewlett-Packard[6], and Novell[7], and is used as an operating system for a wide variety of computer hardware, including desktop computers, supercomputers,[8] and embedded devices such as mobile phones and routers.
Philosophy
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 the most well-known and widely used one. Some free and open source software licences 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 used for the Linux kernel and many of the components from the GNU project.
As an operating system underdog competing with mainstream operating systems, Linux cannot rely on a monopoly advantage; in order for Linux to be convenient for users, Linux aims for interoperability with other operating systems and established computing standards. Linux systems adhere to POSIX,[32] SUS,[33] ISO, and ANSI standards where possible, although to date only one Linux distribution has been POSIX.1 certified, Linux-FT.[34]
Linux is a widely ported operating system. While the Linux kernel was originally designed only for Intel 80386 microprocessors, it now runs on a more diverse range of computer architectures than any other operating system—from the hand-held ARM-based iPAQ to the mainframe IBM System z9, in devices ranging from supercomputers to mobile phones.[35] 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 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, PDAs, Video game consoles, portable music players, and Mobile phones.
Linux 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 RedHat does with Fedora.
In many cities and regions, local associations known as Linux Users Groups (LUGs) seek to promote Linux and by extension free software. They hold meetings and provide free demonstrations, training, technical support, and operating system installation to new users. There are also many internet communities that seek to provide support to Linux users and developers. Most distributions and 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. Linux Weekly News is a weekly digest of Linux-related news; the Linux Journal is an online magazine of Linux articles published monthly; Slashdot is a technology-related news website with many stories on Linux and open source software; Groklaw has written in depth about Linux-related legal proceedings; and there are many articles relevant to Linux on the Free Software Foundation website.
Although Linux is generally available free of charge, several large corporations have established business models that involve selling, supporting, and contributing to Linux and free software. These include Dell, IBM, HP, Sun Microsystems, Novell, and Red Hat. The free software licenses on which Linux is based explicitly accommodate and encourage commercialization; the relationship between Linux 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.
The XO laptop project of One Laptop Per Child is creating a new and potentially much larger Linux community, planned to reach several hundred million schoolchildren and their families and communities in developing countries. Six countries have ordered a million or more units each for delivery in 2007 to distribute to schoolchildren at no charge. Google, Red Hat, and eBay are major supporters of the project.
