| Revision as of 01:25, 12 May 2006 editCentrx (talk | contribs)37,287 edits →Litigation: copyedit; DaimlerChrysler (fully) dismissed in 2004, based on SCO-Linux WP article← Previous edit | Revision as of 01:26, 12 May 2006 edit undoCentrx (talk | contribs)37,287 edits Move "Litigation" section to "History" as a subsection; rename to "SCO Litigation"Next edit → | ||
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| Because ] libraries and programs that form an essential part of all ]s stem from a free operating system project that predates the Linux kernel, ] and the ] ask that the combined system be referred to as "GNU/Linux" or "a Linux-based GNU system". Linus Torvalds has said that he finds calling Linux in general ''GNU/Linux'' "just ridiculous". Some distributions do use this name—notably ''] GNU/Linux''—while most people simply refer to the system as ''Linux''. The distinction between the Linux kernel and entire systems based on it is a source of confusion to many newcomers, and the naming remains controversial. | Because ] libraries and programs that form an essential part of all ]s stem from a free operating system project that predates the Linux kernel, ] and the ] ask that the combined system be referred to as "GNU/Linux" or "a Linux-based GNU system". Linus Torvalds has said that he finds calling Linux in general ''GNU/Linux'' "just ridiculous". Some distributions do use this name—notably ''] GNU/Linux''—while most people simply refer to the system as ''Linux''. The distinction between the Linux kernel and entire systems based on it is a source of confusion to many newcomers, and the naming remains controversial. | ||
| ⚫ | == SCO Litigation == | ||
| ⚫ | {{main|SCO-Linux controversies}} | ||
| ⚫ | In March 2003, the ] (SCO) filed a ] against ] claiming that IBM had contributed portions of SCO's copyrighted code to the Linux kernel in violation of IBM's license to use Unix. Additionally, SCO sent letters to a number of companies warning that their use of Linux without a license from SCO may be actionable, and claimed in the press that they would be suing individual Linux users. This controversy has involved lawsuits by SCO against ], ] (dismissed in 2004), and ], and by ] and others against SCO. | ||
| ⚫ | To date, no proof of SCO's claims of copied code in Linux has been provided and SCO's claims have varied widely. | ||
| === Development efforts === | === Development efforts === | ||
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| The business model of commercial suppliers is generally dependent on charging for support, especially for business users. Some companies offer a special business version of their distribution which adds proprietary support packages and tools to administer higher numbers of installations or do administrative tasks more easily. | The business model of commercial suppliers is generally dependent on charging for support, especially for business users. Some companies offer a special business version of their distribution which adds proprietary support packages and tools to administer higher numbers of installations or do administrative tasks more easily. | ||
| ⚫ | == Litigation == | ||
| ⚫ | {{main|SCO-Linux controversies}} | ||
| ⚫ | In March 2003, the ] (SCO) filed a ] against ] claiming that IBM had contributed portions of SCO's copyrighted code to the Linux kernel in violation of IBM's license to use Unix. Additionally, SCO sent letters to a number of companies warning that their use of Linux without a license from SCO may be actionable, and claimed in the press that they would be suing individual Linux users. This controversy has involved lawsuits by SCO against ], ] (dismissed in 2004), and ], and by ] and others against SCO. | ||
| ⚫ | To date, no proof of SCO's claims of copied code in Linux has been provided and SCO's claims have varied widely. | ||
| == References == | == References == | ||
Revision as of 01:26, 12 May 2006
This article is about the operating system which uses the Linux kernel. For the kernel itself, see Linux kernel. For the asteroid, see 9885 Linux. Operating system | |
| Developer | Various contributers and developers |
|---|---|
| OS family | POSIX-conformant Unix-Clones |
| Working state | In production / development |
| Source model | Open source |
| Latest release | 2.6.16.14 / 2006 |
| Kernel type | Monolithic |
| License | GPL |
| Official website | http://www.kernel.org/ http://www.gnu.org/ http://www.linux.org/ |
Linux (also known as GNU/Linux) is a computer operating system. It is one of the most prominent examples of free software and of open source development; unlike proprietary operating systems such as Windows or Mac OS, all of its underlying source code is available to the public for anyone to freely use, modify, and redistribute.
Initially, Linux was primarily developed and used by individual enthusiasts. Since then, Linux has gained the support of major corporations such as IBM, Sun Microsystems, Hewlett-Packard, and Novell for use in servers and is gaining popularity in the desktop market. It is used in systems ranging from the common personal computer to supercomputers and embedded systems such as mobile phones and personal video recorders. Proponents and analysts attribute its success to its vendor independence (the opposite of vendor lock-in), low cost, security, and reliability.
History
In 1983, Richard Stallman founded the GNU Project, with the goal of developing a complete Unix-like operating system composed entirely of free software. By the beginning of the 1990s, GNU had produced or collected most of the necessary components of this system—libraries, compilers, text editors, a Unix-like shell—except for the core component, the kernel. The GNU project began developing a kernel, the Hurd, in 1990, based on the Mach microkernel, but the development of this Mach-based design proved difficult and proceeded slowly.
Meanwhile, in 1991, another kernel was begun as a hobby by Finnish university student Linus Torvalds while attending the University of Helsinki. Torvalds originally used Minix on his own computer, a simplified Unix-like system written by Andrew Tanenbaum for teaching operating system design. However, Tanenbaum did not permit others to extend his operating system, leading Torvalds to create a replacement for Minix.
Originally, Torvalds called his his kernel "Freax" for "free" and "freak" and with the often-used X in the names of Unix-like systems. The name "Linux" was coined by Ari Lemmke, who administered an FTP server belonging to the Finnish University Network; he invented the name Linux for the directory from which Torvalds' project was first available for download .
At first a computer running Minix was necessary in order to configure and install Linux. Initial versions of Linux also required another operating system to be present in order to boot from a hard disk, but soon there were independent boot loaders such as LILO. The Linux system quickly surpassed Minix in functionality; Torvalds and other early Linux kernel developers adapted their work for the GNU components and user-space programs to create a complete, fully functional, and free operating system.
Today, Torvalds continues to direct the development of the kernel, while other subsystems such as the GNU components continue to be developed separately. Linux kernel development is not and has never been a part of the GNU Project. Other groups and companies combine and distribute these components with additional application software in the form of Linux distributions.
Portability
See also: Linux kernelThe Linux kernel was originally designed only for Intel 80386 microprocessors, but now supports a wide variety of computer architectures. Linux is now one of the most widely ported operating systems, running on a diverse range of systems from the hand-held ARM-based iPAQ to the mainframe IBM System z9. Specialised distributions exist for less mainstream architectures.
Copyright licensing, and the Linux trademark
The Linux kernel and most GNU software are licensed under the GNU General Public License (GPL). The GPL requires that all distributed source code modifications and derived works also be licensed under the GPL, and is sometimes referred to as a "share and share-alike" or "copyleft" license. In 1997, Linus Torvalds stated, "Making Linux GPL'd was definitely the best thing I ever did." Other software may use other licenses; many libraries use the GNU Lesser General Public License (LGPL), a more permissive variant of the GPL, and the X Window System uses the MIT License.
In the United States, the name Linux is a trademark registered to Linus Torvalds. In 1997, after another individual registered the trademark and demanded royalty payments from Linux distributors, Torvalds and some affected organizations sued to have the trademark assigned instead to Torvalds. The licensing of the trademark is now handled by the Linux Mark Institute. Torvalds has stated that he only trademarked the name to prevent someone else from using it, but was bound in 2005 by United States trademark law to take active measures to enforce the trademark. As a result, the LMI sent out a number of letters to distribution vendors requesting that a fee be paid for the use of the name, and a number of companies have complied.
Pronunciation
In 1992, Torvalds explained how he pronounces the word Linux:
- "'li' is pronounced with a short sound: compare prInt, mInImal etc. 'nux' is also short, non-diphthong, like in pUt {IPA /ʊ/}. It's partly due to minix: linux was just my working name for the thing, and as I wrote it to replace minix on my system, the result is what it is... linus' minix became linux."
An audio file of Torvalds saying "Hello, this is Linus Torvalds, and I pronounce Linux as Linux" can be found here. Note that in English, "Linux" and "Minix" are usually pronounced with a short i (IPA: /ɪ/) sound that is different from Torvalds' Finland-Swedish pronunciation of these words.
Linux and the GNU Project
Because GNU libraries and programs that form an essential part of all Linux distributions stem from a free operating system project that predates the Linux kernel, Richard Stallman and the Free Software Foundation ask that the combined system be referred to as "GNU/Linux" or "a Linux-based GNU system". Linus Torvalds has said that he finds calling Linux in general GNU/Linux "just ridiculous". Some distributions do use this name—notably Debian GNU/Linux—while most people simply refer to the system as Linux. The distinction between the Linux kernel and entire systems based on it is a source of confusion to many newcomers, and the naming remains controversial.
SCO Litigation
Main article: SCO-Linux controversiesIn March 2003, the SCO Group (SCO) filed a lawsuit against IBM claiming that IBM had contributed portions of SCO's copyrighted code to the Linux kernel in violation of IBM's license to use Unix. Additionally, SCO sent letters to a number of companies warning that their use of Linux without a license from SCO may be actionable, and claimed in the press that they would be suing individual Linux users. This controversy has involved lawsuits by SCO against Novell, DaimlerChrysler (dismissed in 2004), and AutoZone, and by Red Hat and others against SCO.
To date, no proof of SCO's claims of copied code in Linux has been provided and SCO's claims have varied widely.
Development efforts
More Than a Gigabuck: Estimating GNU/Linux's Size, a study of Red Hat Linux 7.1, found that this particular distribution contained 30 million source lines of code (SLOC). The Linux kernel contained 2.4 million lines of code, or 8% of the total. Using the Constructive Cost Model (COCOMO), the study estimated that this distribution required about eight thousand person-years of development time. Had all this software been developed by conventional proprietary means, it would have cost 1.08 billion dollars (year 2000 U.S. dollars) to develop in the United States. Slightly over half of the code in that distribution was licensed under the GPL.
In a later study, Counting potatoes: the size of Debian 2.2, the same analysis was performed for Debian GNU/Linux version 2.2. This distribution contained over fifty-five million source lines of code, and the study estimated that it would have cost 1.9 billion dollars (year 2000 U.S. dollars) to develop by conventional proprietary means.
Applications
Linux's low cost, flexibility and Unix background make it suitable for a wide range of applications.
Linux is the cornerstone of the so-called LAMP server-software combination (Linux, Apache, MySQL, Perl/PHP/Python) which has achieved widespread popularity among Web developers, making it one of the most common platforms on the Web. A prominent example of this software combination in use is MediaWiki — the software primarily written for Misplaced Pages.
The video game industry will see Linux more accessible to gamers with the 2006 launch of the Sony PlayStation 3 video game console which will run Linux out of the box. Sony has previously released a PS2 Linux kit for their PlayStation 2 video game console. Developers like Atari, id Software, and the US Army regularly release titles to the Linux desktop.
Linux is also often used in embedded systems. Its low cost makes it particularly useful in set-top boxes and for hand-held devices such as the Simputer, a computer aimed mainly at low-income populations in developing nations. In mobile phones, Linux has become a major competitor to the proprietary Symbian OS software and in handheld devices, it is an alternative to the Windows CE and Palm OS operating systems (PalmSource has stated that future versions of Palm OS Cobalt will be built as a layer on top of the Linux kernel). The popular TiVo digital video recorder uses a customized version of Linux. A large number of network firewalls and routers use Linux internally, taking advantage of the advanced firewalling and routing capabilities built in the kernel itself. The TomTom satellite navigation system uses an embedded version of the Linux kernel. Linux is also expanding into telecommunications equipment through efforts such as Carrier Grade Linux.
Linux is increasingly common as an operating system for supercomputers. In the November 2005 TOP500 list of supercomputers, the 2 fastest supercomputers in the world run Linux. Of the 500 systems, 73.2% run some version of Linux, including 7 of the top 10.
Distributions
Further information: Linux distributionLinux is predominantly used as part of a Linux distribution (commonly called a 'distro'). These are compiled by individuals, loose-knit teams, and various professional organizations. They commonly include additional system software and applications, an installer system to ease initial system setup and simplified management of component updates. Distributions are created for many different purposes, including localization, architecture support, real-time applications, and embedded systems, and many deliberately include only free software. Over 450 distributions are available .
A typical general-purpose distribution includes the Linux kernel, some GNU libraries and tools, command-line shells, the graphical X Window System and an accompanying desktop environment such as KDE or GNOME, together with thousands of application software packages, from office suites to compilers, text editors, and scientific tools.
Desktop usage
The high level of access granted to Linux's internals has led to Linux users traditionally tending to be more technologically oriented than users of Microsoft Windows and Mac OS, sometimes revelling in the tag of "hacker" or "geek". Linux and other free software projects have been frequently criticized for not going far enough in terms of ensuring ease of use.
This stereotype has begun to be dispelled in recent years. Linux may now be used with a user interface that is very similar to those running on other operating systems. Users might have to switch application software, and there may be fewer options (as in the case of computer games) but there usually exists a replacement of at least sufficient quality, and general applications like spreadsheets, word processors, and browsers are available for Linux in profusion. A growing number of proprietary software vendors are supporting Linux.
Linux's Unix roots mean that while graphical configuration tools and control panels are available for many system settings and services, plain-text configuration files are still commonly used to configure the OS and may be exposed to users. On the command shell, many usability hangups from early Unix days generally remain, such as the inability to undo many operations such as file deletion and inconsistency of interface of many older programs.
The Berlin-based organization Relevantive, which specializes in providing consultation to companies on the usability of software and Web services, concluded in 2003 that the usability of Linux for a set of desktop-related tasks was "nearly equal to Windows XP." Since then, there have been numerous independent studies and articles which indicate that a modern Linux desktop using Gnome or KDE is on par with Microsoft Windows in a business setting.
Market share and uptake
Further information: Linux adoptionAccording to the market research company IDC, 25% of servers and 2.8% of desktop computers ran Linux as of 2002.
The Linux market is rapidly growing and is projected to exceed $35.7 billion by 2008 . It is perhaps important to note that this figure may not be truly reflective of uptake given that the Linux operating system itself is free to use, modify and distribute, although this does not necessarily indicate a lower total cost of ownership comparing to alternatives.
The paper Why Open Source Software / Free Software (OSS/FS)? Look at the Numbers! identifies many quantitative studies of open source software, on topics including market share and reliability, with many studies specifically examining Linux.
Installation
In the past, difficulty of installation was a barrier to wide adoption of Linux-based desktop systems. Many distributions are now at least as easy to install as a comparable version of Windows. It is unnecessary to file license numbers and enter them during installation and it is not normally necessary to install drivers after installing Linux, as most hardware is supported out of the box.
As with servers, personal computers that come with Linux already installed are available from vendors including Hewlett-Packard and Dell, although generally only for their business desktop line.
The most common method of installing Linux on a personal computer is by booting from a CD that contains the installation program and installable software. Such a CD can be burned from a downloaded ISO image, purchased alone for a low price, or can be obtained as part of a box set that may also include manuals and additional commercial software.
Alternatives include thin client installation and running directly from a LiveCD.
On embedded devices Linux is typically held in the device's firmware and may or may not be consumer-accessible.
Programming on Linux
The GNU Compiler Collection is by far the most commonly-used compiler family on Linux, providing frontends for C, C++ and Java amongst others. There are also a number of closed source compilers available for better performance. Companies that provide these compilers include: Intel, PathScale, and the Portland Group. There are a number of IDEs available for Linux including Anjuta, KDevelop, NetBeans IDE and Eclipse, with extensible editors such as Emacs also remaining widely used. Linux is as suited to scripting languages as other Unix variants and in addition to shell programming most Linux distributions come installed with Python, Perl, PHP and Ruby.
Support
Technical support is provided by commercial suppliers and by other Linux users, usually in online forums, newsgroups and mailing lists. Linux User Groups (LUGs) have traditionally been organised to provide local support for Linux.
The business model of commercial suppliers is generally dependent on charging for support, especially for business users. Some companies offer a special business version of their distribution which adds proprietary support packages and tools to administer higher numbers of installations or do administrative tasks more easily.
References
- Glyn Moody: Rebel Code: Linux and the Open Source Revolution, Perseus Publishing, ISBN 0-713-99520-3
- Gedda. R. (2004). Linux breaks desktop barrier in 2004: Torvalds. Retrieved January 16 2004 from
- Mackenzie, K. (2004). Linux Torvalds Q&A. Retrieved January 19 2004 from
- More Than a Gigabuck: Estimating GNU/Linux's Size by David A. Wheeler
- Counting potatoes: the size of Debian 2.2 by Jesús M. González-Barahona et al.
- Why Open Source Software / Free Software (OSS/FS)? Look at the Numbers! by David A. Wheeler
- Desktop Linux: Ready for Prime Time? by Emmett Dulaney, Redmond Magazine, June 2005, retrieved on 21 December 2005
- Mandrake 8.1 easier than Win-XP by Thomas C. Greene, The Register, retrieved December 22 2005
See also
General
Eric S. Raymond's essay The Cathedral and the Bazaar discusses the development model of the Linux kernel and similar software.
Lists
Magazines
Documentaries
Footnotes
- Burke, Steven (2006-03-20). "Red Hat looks to boost channel sales". CRN. Retrieved 2006-04-01.
{{cite news}}: Check date values in:|date=(help) - "Linux Anecdotes". Retrieved 2006-04-01.
- "Linus Torvalds interview". Retrieved 2006-05-08.
- "U.S. Reg No: 1916230". Retrieved 2006-04-01.
- "Torvalds explanation of how to pronounce Linux". Retrieved 2006-04-01.
- "More Than a Gigabuck: Estimating GNU/Linux's Size". Retrieved 2006-04-01.
- "An Open Letter from PalmSource to the Linux Community". Retrieved 2006-04-01.
- "The LWN.net Linux Distribution List". Retrieved 2006-04-01.
- "The Global Desktop Project, Building Technology and Communities". Retrieved 2006-05-07.
- Blau, John (2003-08-04). "Study: Linux nears Windows XP usability". IDG News Service. Retrieved 2006-04-03.
{{cite news}}: Check date values in:|date=(help) - "Relevantive Linux usability study". Retrieved 2006-04-03. (In PDF format here)
- "Desktop Linux: Ready for Prime Time?". Retrieved 2006-04-01.
- "Microsoft eyes up a new kid on the block, writes Dominic White". Retrieved 2006-05-07.
- "Linux To Ring Up $35 Billion By 2008". Retrieved 2006-04-01.
- "Why Open Source Software / Free Software (OSS/FS)? Look at the Numbers!". Retrieved 2006-04-01.
External links
General
- Linux.org - contains comprehensive information and resources about Linux.
- Linux.com - commercial news site.
- The Linux Documentation Project
- Linux zone of developerWorks - contains articles, tutorials, and tips to help developers with Linux application development and system administration.
- Kernel.org - development.
Distribution related
- Distro Quiz — a test that recommends a distribution based on the answers.
- Linux Distribution Chooser — another distro recommendation tool
- Linux Online — distributions and FTP sites (sortable by categories)
- DistroWatch.com — distribution information & announcements.
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