Linux

Unix-like computer operatin seestem

Linux (kent as GNU/Linux an aw) is ae Unix-like computer operatin seestem. It is ane o the maist kenspeckle examplars o open soorce development an free saftware; unlik proprietary operatin seestems sic as Microsoft Windows or Mac OS X, its unnerlyin soorce code is tae haunde for onybody tae uise, chynge, an caw aboot for nae chairge.

First developit an uised tae the maist pairt bi single enthusiasts oan personal computers, Linux haes nou gained the support o muckle companies sic as IBM, Sun Microsystems, Hewlett-Packard, an Novell, Inc., an haes risen tae prominence as an operatin seestem for servers; aicht o the ten maist reliable internet hostin companies nou rins Linux oan thair wab servers.[1]

Linux haes been mair widely portit tae deifferent computin platforms nor ony ither operatin seestem. It is uised in devices reengin frae supercomputers tae mobile phones, an is gainin popularity in the personal computer mercat.[2]

History

Linus Torvalds, creautor o the Linux kirnel.

In 1983, Richard Stallman foondit the GNU Project, wi the ettle o developin ae complete Unix-like operatin seestem composit haily o free saftware. Bi the stairt o the 1990s, GNU haed creatit or collectit maist o the necessar components o this seestem — librars, compilers, text editors, ae Unix shell — except for the core component, the kirnel. The GNU project stairtit developin ae kirnel, the GNU Hurd, in 1990, foodit oan the Mach microkirnel, but the development o this Mach-basit design haes pruiven gey haurd an proceedit slaw.

In atween times, in 1991, anither kirnel wis begoud as ae habby bi Finnish varsity student Linus Torvalds while attendin the Varsity o Helsinki.[3] Torvalds oreeginally uised Minix oan his ain computer, ae simplifee'd Unix-like seestem written bi Andrew Tanenbaum for learnin operatin seestem design. Forby thon Tanenbaum didna allou ithers tar rax his operatin seestem, leadin Torvalds tae big ae replacement for Minix.

Oreeginally, Torvalds cried his kirnel "Freax" for "free" an "freak" an wi the aften-uised X in the names o Unix-like seestems. The name "Linux" wis cleckit bi Ari Lemmke, wha admeenistert an FTP server aucht the Finnish Varsity Network; he cleckit the name Linux for the directory that Torvalds' project wis first tae hund for dounlade frae.[4]

At first ae computer rinnin Minix wis necessar for tae confeegur an instaw Linux. Ineetial versions o Linux needit anither operatin seestem tae be present for tae boot frae ae haurd disk, but suin thare war independent boot laders sic as LILO. The Linux seestem quickly surpassed Minix in functionality; Torvalds an ither early Linux kirnel developers adaptit thair wark for the GNU components an uiser-space programmes for tae creaut ae hale, fully functional, an free operatin seestem.

The day, Torvalds conteenas tae guide the oncome o the kirnel, while ither subseestems sic as the GNU components conteeas tae be developit separate (Linux kirnel development isna pairt o the GNU Project). Ither groups an companies combines an distributes thir components wi addeetional application saftware in the form o Linux distributions.

Portability

see an aw: Linux (kirnel) / Portabeelity

The Linux kirnel wis oreeginally designed anerly for Intel 80386 microprocessors, but nou uphauds ae braid hatter o computer architectures. Linux is ane o the maist waften portit operatin seestems, rinnin oan ae diverse reenge o seestems frae the haund-hauden ARM-basit iPAQ tae the mainframe IBM System z9. Speecialized deestributions exists for less mainstream architectures.

Copyricht, licensin, an the Linux tredemerk

The Linux kirnel an maist GNU saftware is licensed unner the GNU General Public License. The GPL requires that aw deestributit soorce code modifications an derived warks be licensed unner the GPL an aw, an is whiles cried a "share an share-alike" or "copyleft" license. Qho Linus Torvalds in 1997 "Making Linux GPL'd was definitely the best thing I ever did."[5] Ither saftware micht uise ither licenses; mony librars uises the GNU Lesser General Public License (LGPL), ae mair permissive variant o the GPL, an the X Window System uises the MIT License.

In the Unitit States, the name Linux is ae tredemerk[6] registert tae Linus Torvalds. Initially, naebody registert it, but oan August 15, 1994, William R. Della Croce, Jr. filed for the tredemerk Linux, an syne demaundit ryalties frae Linux deestributors. In 1996, Torvald an ae wheen affectit organisations sued for tae hae the tredemerk assigned tae Torvalds, an in 1997 the case wis settelt[7]. The licensin o the tredemerk is nou haundelt bi the Linux Mark Institute. Torvalds haes statit that he juist tredemerkit the name for tae hinder ither bodies frae uisin it, but wis bund in 2005 bi Unitit States tredemerk law tae tak active meisurs tae uphaud the tredemerk. The affcome wis that the LMI sent oot ae nummer o letters tae deestribution vendors speirin that ae fee be peyed for the uiss o the name, an ae wheen companies haes complee'd.[8]

Pronunciation

In 1992, Torvalds expponed hou he soonds the wird Linux:

'li' is pronounced wi ae short [ee] sound: compare prInt, mInImal etc. 'nux' is an aw ae short, non-diphthong, like in pUt {IPA /ʌ/}. It's pairtly 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.

— Linus Torvalds, comp.os.linux newsgroup[4]

Ae soond file o Torvalds sayin "Hello, this is Linus Torvalds, and I pronounce Linux as Linux" can be fund here. Merk that in Inglis, "Linux" an "Minix" is for ordinar soodit wi ae cutty i (IPA: /ɪ/) soond that differs frae Torvalds' Finland-Swedish soondin o thir wirds, seemilar tae the differ atween the Finland-Swadish an Inglis soondins o "Linus." The Finland-Swedish soondin {IPA /'linʌks/} hauds tae Scots phonology an aw.

Linux an the GNU Project

The ettle o the GNU project is tae produce ae Unix-compatible operatin seestem conseestin haily o free saftware, an maist general-purpose Linux distributions relies oan librars an tuils written tae that effect. The Free Software Foundation sees thir Linux distributions as "variants" o the GNU seestem, an asks that sic operatin seestems be referred tae as GNU/Linux or a Linux-basit GNU seestem. While some distributions maks ae pynt o uisin the soudert form - for ordinar Debian GNU/Linux - its uiss ootwi the enthusiast community is leemitit, an Linus Torvalds haes said that he finds cryin Linux in general GNU/Linux "just ridiculous" [9]. The disteenction atween the Linux kirnel an distributions foondit oan it is ae soorce o raivelment tae mony newcomers, an the namin bides controversial.

SCO litigation

In Mairch 2003, the SCO Group pit in ae lawsuit agin IBM, thrapin that IBM haed contributit pairts o SCO's copyrichtit code tae the Linux kirnel in veeolation o IBM's leecense tae uise Unix. Mair oot ower, SCO sent letters tae ae wheen companies wairnin that thair uiss o Linux athoot ae leecense frae SCO micht be actionable, an threapit in the press that thay wad be lawin indiveedual Linux uiser. This controversy haes involved lawsuits bi SCO agin DaimlerChrysler (dismissed in 2004), an AutoZone, an bi Red Hat an ithers agin SCO. Furthermair, whither SCO e'en awns the relevant Unix copyrichts is currently disputit bi Novell.

As per the Utah Destrict Coort rulin oan Juilie 3rd, 2006; 182 claims oot o 294 claims made bi SCO agin IBM haes been dismissed.[10]

SCO's threaps haes varied widely. As o 2006, nae pruif o SCO's claims o copied code in Linux haes been providit.

Development

More Than a Gigabuck: Estimating GNU/Linux's Size, ae 2001 study o Red Hat Linux 7.1, foond that this distribution contained 30 million soorce lines o code.[11] Uisin the Constructive Cost Model, the study estimatit that this distribution required aboot aicht thoosand man-years o development time. Accordin tae the study, if aw this saftware haed been developit bi conventional proprietary means, it wad hae cost aboot 1.08 billion dollars (year 2000 U.S. dollars) tae develop in the United States.

The majority o the code (71%) wis written in the C programmin language, but mony ither leids war uised, includin C++, Lisp, assembly language, Perl, Fortran, Python an various shell scriptin leids. Slichtly ower hauf o aw lines o code war licensed unner the GPL. The Linux kirnel wis 2.4 million lines o code, or 8% o the total.

In ae later study, Counting potatoes: The size of Debian 2.2, the same analysis wis performed for Debian GNU/Linux version 2.2.[12] This distribution contained ower fifty-five million soorce lines o code, an the study estimatit that it wad hae cost 1.9 billion dollars (year 2000 U.S. dollars) tae develop bi conventional means.

Applications

A KDE desktop oan the SUSE distribution.

Linux haes historically been uised mainly as ae server operatin seestem, but its law cost, flexibility, an Unix background mak it suitable for ae wide reenge o applications.Linux is the cornerstone o the "LAMP" server-saftware combination (Linux, Apache, MySQL, Perl/PHP/Python) which haes achieved popularity amang developers, an which is ane o the mair common platforms for wabsite hostin.

Due tae its law cost an its heich configurability, Linux is eften uised in embedded seestems sic as telly set-top boxes, mobile phones, an handheld devices. Linux haes acome ae major competitor tae the proprietary Symbian OS foond in mony mobile phones, an it is an alternative tae the dominant Windows CE an Palm OS operatin seestems oan handheld devices. The popular TiVo digital video recorder uises ae customized version o Linux. Several network firewall an router standalone products, includin several frae Linksys, uise Linux internally, uisin its advanced firewallin an routin capabilities.

Linux is increasingly common as an operatin seestem for supercomputers. In the November 2005 TOP500 leet o supercomputers, the twa fastest supercomputers in the warld ran Linux. O the 500 seestems, 371 (74.2%) ran some version o Linux, includin seiven o the tap ten.

The Sony PlayStation 3 video game console, scheduled tae be releasit in November 2006, will rin Linux bi default. Sony haes previously releasit ae PS2 Linux dae-it-yourself kit for thair PlayStation 2 video game console. Game developers like Atari an id Software hae releasit titles tae the Linux desktop. Linux Game Publishing an aw produces gemmes for Linux, licensing an portin them frae thair Windows soorce code.

The One Laptop Per Child project, which aims tae provide computin devices tae aw childer in developin nations, uises Linux as the devices' operatin seestem.

Distributions

Linux is predominantly uised as pairt o ae Linux distribution (commonly cried ae "distro"). Thir are compiled bi individuals, loose-knit teams, an commercial an volunteer organisations. Thay commonly include additional seestem an application saftware, an installer seestem tae ease initial seestem setup, an integrated management o saftware installation an upgradin. Distributions are creatit for mony deifferent purposes, includin computer architecture support, localization tae ae specific region or language, real-time applications, an embedded seestems, an mony deliberately include anly free saftware. Currently, ower three hunder distributions are actively developit, wi aboot ae dozen distributions bein maist popular for general-purpose uise.[13]

Ae teepical general-purpose distribution includes the Linux kirnel, some GNU librars an tuils, command-line shells, the graphical X Window Seestem an accompanyin desktop environments sic as KDE or GNOME, thegither wi thoosands o application saftware packages, frae office suites tae compilers, text editors, an scienteefic tuils.

Desktop usage

A GNOME desktop rinnin frae the Ubuntu LiveCD.

The heich level o access granted tae Linux's internals haes led tae Linux uisers tradeetionally tendin tae be mair technologically oriented than uisers o Microsoft Windows and Mac OS, whiles revellin in the tag o "hacker" or "geek". Linux an ither free saftware projects hae been frequently criticized for nae goin far enough tae ensure ease o uise.[citation needit]

This stereotype haes begun tae be dispelled in recent years. Linux mey nou be uised wi ae uiser interface that is gey seemilar tae those rinnin oan ither operatin seestems. Uisers mey hae tae switch application saftware, an thare are eften fewer "kent" options (as in the case o computer games) but thare exist replacements for aw general-purpose saftware, an general applications like spreadsheets, wird processors, an browsers are available for Linux in profusion. Additionally, ae growin nummer o proprietary saftware vendors are supportin Linux,[14] and compatibility layers sic as the Wine seestem allou some Windows application saftware an drivers tae be uised oan Linux wioot requirin the vendor tae adapt them.

Linux's roots in the Unix operatin seestem mean that in addition tae graphical configuration tuils and control panels available for mony seestem settins and services, plain-text configuration files are still commonly uised tae configure the OS and can readily be made accesible (or nae) tae uisers, at the administrator's will.

The Berlin-basit organisation Relevantive concluded in 2003 that the usability o Linux for ae set o desktop-relatit tasks wis "nearly equal to Windows XP."[15] Syne then, thare hae been numerous independent studies and articles which indicate that ae modren Linux desktop uisin aither GNOME or KDE is on par wi Microsoft Windows in ae business settin.[16]

Mercat share and uptake

Accordin tae the mercat research company IDC, 25% o servers and 2.8% o desktop computers ran Linux as o 2004.[17] Proponents and analysts attribute the success o Linux tae its security, reliability,[18] law cost, an freedom frae vendor lock-in,[19]. The frictional cost o switchin and lack o support for some hardware and mony application programs designed for Windows, especially gemmes or uncommon business saftware, are twa important factors inhibitin adoption.

The Linux mercat is rapidly growin and the revenue o servers, desktops, an packaged saftware rinnin Linux is expected tae exceed $35.7 billion bi 2008.[20] The actual installed uiser base mey be higher than indicated bi this figure, as maist Linux distributions and applications are freely available and redistributable.

The paper Why Open Source Software / Free Software (OSS/FS)? Look at the Numbers![21] identifies mony quantitative studies o open soorce saftware, oan topics includin mercat share and reliability, wi mony studies specifically examinin Linux.

Installation

The maist common method o installin Linux oan ae personal computer is bi bootin frae ae CD-ROM that contains the installation program and installable saftware. Sic ae CD can be burned frae ae downladed ISO image, purchased alone for ae law price, can be obtained as pairt o ae box set that mey an aw include manuals and additional commercial saftware an in ae wheen cases shipped for free bi request. Mini CD images allou Linux tae be installed frae ae disk wi ae small form factor.

As wi servers, personal computers that come wi Linux already installed are available fra vendors includin Hewlett-Packard and Dell, awtho generally anly for thair business desktop line.

Alternatives tae traditional desktop installation include thin client installation, whaur the operatin seestem is laded and rin frae ae centralised machine ower ae netwark connection; and rinnin frae ae Live CD, whaur the computer boots the entire operatin seestem frae CD wioot first installin it oan the computer's haurd disk.

Oan embedded devices, Linux is teepically held in the device's firmware and mey or mey nae be consumer-accessible.

Programmin oan Linux

The GNU Compiler Collection (GCC) is the standard compiler faimily for maist seestems. Amongst ithers, GCC provides frontends for C, C++ and Java. Maist distributions come installed wi interpreters for Perl, Python and ither scriptin languages, and several nou include C# via the Mono project.

Thare are ae nummer o Integrated development environments available includin KDevelop, Anjuta, NetBeans, and Eclipse while the traditional editors Emacs and Vim remain popular.[citation needit]

The twa main widget tuilkits uised for contemporary GUI programmin are Qt and the Gimp Toolkit, kent as GTK+.

As well as thir free and open soorce options, thare are proprietary compilers and tuils available frae ae reenge o companies sic as Intel,[22] PathScale[23] and the Portland Group.[24]

Support

Technical support is providit bi commercial suppliers and bi ither Linux uisers, uisually in online forums, IRC, newsgroups, and mailin lists. Linux Uiser Groups hae tradeetionally been organisit tae provide support for Linux in specific ceeties and regions.

The business model o commercial suppliers is generally dependent oan chargin for support, especially for business uisers. Ae nummer o companies offer ae specialisit business version o thair distribution, which adds proprietary support packages and tuils tae administer higher nummers o installations or tae simplify administrative tasks.

See an aw

  • List o Linux distributions
  • Comparison o Linux distributions
  • The Cathedral and the Bazaar
  • Total cost o ownership
  • One page Linux reference

References

Fremmit airtins