Kernel (kernel) takes care of managing the hardware andprovides the environment necessary for the operation of the application software, memory addresses, manage processes, administers multitasking and multiuser capabilities of the system and also contains drivers for various hardware devices.
By itself, however, the core is unusable without the shell (shell)and applications they use for various tasks such as creatingand storing files or editing, copying and moving them todifferent locations on the file system. The shell acts as an interface between the kernel and user.
A more popular language what gives fullness of Linux, is itsgraphical shell - system XFree86, called for easier X11 or justX (the "X") and the vast sea of software that spreads to her. All this we also call summarizing Linux.
How Linux is free? What is the difference between open and free?
In the wake of fierce battle looming patent and licensing rights for major software corporations in the 80s of last century, Richard Stallman founded the project GNU, which aims to develop a programming environment and applications that are not subject to a specific company and develop volunteers andvolunteer for the needs of everyone. The project aims topreserve the original status of the software as a subjectprimarily of free artistic and scientific activities rather than purecommerce. The main inspirer of the project Richard StallmanFree Software Foundation (Free Software Foundation)creates a special license - GPL (GNU Public License), which protects freedom of software, it prevents the assignment andimpose restrictions on access to the source program text by of commercial entities.
GPL license allows you to use the software without restriction, to distribute it, even sell it, but they are obliged to provide free and charging access to the source program text and the changes that you made it. Therefore, proponents of this license resist the notion that free necessarily mean free. They insist free word be understood as freedom (freedom), not asfree beer (free beer). Free software is software that allows the user to use it, modify and distribute without restrictions.
What does it mean that Linux is open source?
For people who have so far benefited only "closed" software, the term "open source" sounds a bit enigmatic. The explanation is actually simple. Programmers write software in different languages, which have their own formal rules andsyntax. In this kind of programs are standard text files that canbe edited with the simple text editor like Notepad. This iscalled source program text (source). Regardless of thelanguage when it came time to work program has to be executed by the CPU, it must be "translated" his language and turn it into machine code.
Program texts written in C or C ++ - the most commonly usedlanguages for modern operating systems undergo a process called compilation. Special application - compiler - they'translate' machine language and as a result receiveexecutable files, also called binary (binaries). If you try to openan executable file in a text editor, you will see a series ofincomprehensible symbols.
In "closed" commercial software like MS Windows, we have only the final result - the compiled code, binary files. Free software under the license GPL, distributed mandatory and itssource texts (source), and often published only as a source text. This means that you will have to compile it yourself to use it. In the Linux world, however, this procedure is simple andrequires no programming knowledge and means to do so are also available and free. Need to provide the source code is clear - a program can be changed only if you have her withsource.
Why choose Linux?
The causes are multiple and can be of different nature. First, the drawbacks of the Linux are much less merit. Let financialreasons that have no competition. The use of licensed software for amateur and professional needs in the world ofopen source does not necessarily mean inflated costs.Moreover, most often is not associated with any costs. Let's see what else Linux differs from other popular operating systems.
Born on the Web. This means that it is designed to support all kinds of network protocols and strive for maximumcompatibility with other platforms such as Windows, Apple, Novell and various standards. His power will be released yetby transforming the global network in lifestyle for the modern man.
With open source software text. We explained what that means, but not mentioned why it is so great advantage.Develops millions of programmers, programming errors andsecurity problems are sometimes removed in less than one hour (!). Unix-like system by nature is "immune" to viruses, which explains why it is the preferred platform for deliveringInternet services.
Is free (not necessarily free!). Does not belong to a particular person or company. Users use it without conditions and restrictions, and developers can also benefit from unlimitedsource program text and change it to suit your needs.Attention! They must also publish without conditions changes they made, if they want to sell or distribute the software.
For more professionally oriented users is irrelevant that Linuxis a modern multitasking operating system that supports all hardware architectures - from IBM Mainframe to handheld-computers.
Linux-distributions: what are they?
Already mentioned that Linux is just the kernel. Without the sheath and innumerable applications, it is not very functionalfrom the perspective of the user. Back in 1992, when Linux isstill at an early stage of development and there are not manyapplication software for it appeared the first collection of pre-configured and compiled Linux-kernel complete with binary.Thus were born the first distributions such as SLS, later calledSlackware, Patrick Volkerding, which first spread on diskettes,and then on CD.
Today there are dozens of Linux-distributions with different volume and different needs. Some of them are developedcompletely voluntary and strictly adhere to the definition ofopen source Debian - the largest distribution of over 9000software packages. Others are sold for small or large amountsdepending on the amount involved in these commercial software. More expensive than software often hasdocumentation without which our hands are tied. You can use free intended for the home user or business distributionscompanies such as Red Hat, Mandrake or SuSE, but if you want to count on the support or use a dedicated serversolutions will have to pay.
Modern distributions compete in quality maintenance, timelysoftware updates and ease of management. Most of themalready have a convenient graphical tools for installation and configuration, making them available for use by novice users.
[See also: Distributions]
Is there an ideal distribution?
Highly recommended for beginners or do for experimenterswho want to see "live" real running Linux, without risking the integrity of your system, leaving the hard drive intact, is the distribution Knoppix. It is unique in several things:
fits on one CD, and contains over 600 programs for all needsof a desktop system, incl. Multimedia software and office suiteOpenOffice.org, and also the program WINE, which you canrun applications for Windows;
not installed on the hard drive, loaded from CDROM anddecompress in real time;
recognize and automatically configure all of the hardware, nothaving to touch anything in the configuration;
loaded directly into graphics mode using beautiful desktopmanager for KDE3;
can be installed on the hard drive and to become a classicDebian - one of distributions known for its stability and ability,but also with their difficult accessibility for beginners;
All that said distribution must be taken with a degree ofconditionality and in no way should he gives absoluteimportance. It is important to know that any distribution to choose, in its work on the same kernel - Linux, the samecommand line - that of Unix, the same principles are to manage multitasking and multiuser capabilities of the system,and a same is the file system hierarchy.
In fact, the distributions are different ways to achieve a goal.No bad distribution is poor management. True, some distributions are suffering from chronic diseases such asgreed memory or instability of the software and this is the maincriterion by which a user choose the harsher options, but oftenprove more reliable. Preferences and favorite distro has aLinux-user. In this case, the end justifies the means. Almost every distribution can be used for anything but Slackwaresetup for home use would take longer and require more knowledge than Knoppix.
It was 1991 and the agony of the Cold War gradually passed by. Prevailed an atmosphere of peace and tranquility. In the computer field, the wonderful future seemed very close against the powerful hardware that raised the bar higher than anyonehad expected.
But still, something was missing.
And not just anywhere, but in operating systems, where it hadappeared a large gap.
First, DOS still ruled in the vast empire of personal computers.Bought by Seattle hacker for $ 50,000, this ungainly OS hadcrept into every corner of the world through an efficient andsmart marketing strategy. PC users had no choice. Mac-s ofApple were better, but the astronomical price that nobodycould afford, they remained out of sight of millions of eagerconsumers.
The other camp was the world of Unix. But Unix itself was even more expensive. In search of "big money" Unix vendors placedmuch higher prices that PC users to stay off. The source codeof Unix, once taught in universities received the favor of Bell Labs, was now carefully guarded and not published. And toincrease neudovledvorenostta of PC users around the world,major players in the software market failed to provide aneffective solution to the problem.
One solution seemed to appear in the form of MINIX. AndrewTanenbaum (Andrew S. Tanenbaum), a Dutch professor whowanted to teach his students how working within a realoperating system, it was written from scratch. MINIX wasdesigned to run on Intel microprocessors 8086 which had flooded the market.
As an operating system, MINIX was not superb. But had the advantage that its source code was available. Anyone whosomehow get the book 'operating system' by Tanenbaumcould get 12,000 lines of code written in C and assembler. For the first time, every aspiring programmer or hacker could readthe source code of the operating system, which to date,software vendors jealously guarded. Being an excellent author,Tanenbaum managed to attract the brightest minds incomputer science thorough and untainted, live discussionabout art "to create an operating system." Students studyingcomputer science in the world, flew the book, reading the code to understand the system that handles their computers.
One of them was Linus Torvalds (Linus Torvalds).
b. "new kid on the block"
In 1991, Linus Benedict Torvalds (Linus Benedict Torvalds)was a sophomore studying computer science at the University of Helsinki, and also a self-taught hacker. Twenty-one year oldblond and polite Finn loved to tinker with computers, itattracted the power and range, which can be increased it. But what I lacked, was an operating system that can meet the requirements of professional. MINIX was good, but still, it wasonly operating system for students, created as a teaching tool, not as powerful operating system with industrial relevance.
At that time, developers around the world have been stronglyinspired by the GNU project Richard Stallman (Richard Stallman), software movement set itself the goal to providefree and quality software. Revered as a cult hero in the realm of computing, Stallman began his impressive career in the famous Artificial Intelligence Laboratory at the MassachusettsInstitute of Technology (MIT), and in the second half of theseventies created editor emacs. In the early eighties, companies making commercial software lured many brilliantprogrammers in the laboratory and agreed new constraints of confidentiality to protect their secrets. But Stallman hadanother vision. His idea was that unlike other products, the software must be free from restrictions against copying and changes to be made better and more efficient computer programs. With his famous manifesto of 1983 declared aproject GNU, he launched a movement to create and distribute software appropriate to his philosophy (by the way, the nameGNU is a recursive acronym which actually means "GNU is notUNIX" ). But to achieve this dream of creating a completelyfree operating system, it must first create the tools. So in 1984,Stallman began writing GNU C compiler (GCC) - surprisingachievement for a programmer working alone. With hislegendary technical ingenuity, he himself brings shame toentire groups of programmers from software companies with the creation of GCC, regarded as one of the most effectiveand clearest compilers ever created.
By 1991, the GNU project created a lot of tools. The long-awaited GNU C compiler was ready, but still no operating system. Even MINIX had to be licensed. Working on core GNU - HURD, but was not expected to be ready in the next fewyears.
This delay was too large for Linus.
On August 25, 1991 the historical message was sent to the news group MINIX Linus:
From: torvalds@klaava.Helsinki.FI (Linus Benedict Torvalds)
Subject: What would you like to see most in minix?
Summary: small poll for my new operating system
Date: 25 Aug 91 20:57:08 GMT
Organization: University of Helsinki
Hello, folks enjoying minix,
I do a (free) operating system (just a hobby, will not be something big and
professional like gnu) for 386 (486) AT computers. I'm working on this from
April and began to acquire finished. I'll be glad of any comments -
what you like and what - not in minix bp my OS many like him
(physical organization of the file system (due to practical reasons)
among other things). Fully ported bash (1.08) and gcc (1.40),and things
seems rabotyat.Tova means that you will have something practical to
few months and would like to know what new features people would like. any
is welcome, but I promise I will accomplish all:-)
PS. Yes - do not use any code of minix, and the file system ismultithreaded.
NOT portable (uses 386 task switching etc. Below.) And most likely never
supports nothing but AT hard disks, and that's all
As it is evident from posting even Linus did not believe that hiscreation will be large enough to change the world of computingforever. Linux 0.01 was released in mid-September 1991 andwas put on the Web. Enthusiasm about this "new kid on the block" is increasing and the code was downloaded, tested,tweaked and sent back to Linus. Version 0.02 one release on October 5, with this famous statement from Linus:
From: torvalds@klaava.Helsinki.FI (Linus Benedict Torvalds)
Subject: Free minix-like kernel sources for 386-AT
Date: 5 Oct 91 05:41:06 GMT
Organization: University of Helsinki
Do you suffer for the good days of minix-1.1, when men were real men and wrote their own device drivers? Maybe you haveother
without a "good" project and now sharpening their teeth forwhich OS you can try to change for their
needs? Do not you find frustrating that everything works onminix? No longer spend nights with an attempt to make a program to
work? Then, this posting may be right for you:-)
As I mentioned a month (?), Working on a free version of aminix likeness for AT-386 computers. Finally,
reached the stage where they can now be used (although itmay not, depending
what you want to do) and I would like to provide source code for wider dissemination. This is just version 0.02 (+1 (very
small) patch), but I've successfully put bash / gcc / gnu-make / gnu-sed / compress and t.pod.
Source code of this project can be found on nic.funet.fi (126.96.36.199) in the directory / pub / OS / Linux.
The directory also contains some README file and severalexecutable file to work under linux
(bash, update and gcc; what more can one wish:-). It is available in full source code of the kernel bp not used any codeof minix
Source code libraries are only partially free, so that they canbe distributed at this stage. The system can be compiled
"as-is" and as far as I know works. Hmm. Source code, binaries (bash and gcc) can be found and
the same place in / pub / gnu.
Linux version 0.03 came out a few weeks. By December cameversion 0.10. Linux was still depart slightly from its originalscaffold-like shape. AT only supports hard disks, no login (charged directly bash). Version 0.11 was much improved -with support for multilingual keyboards drivers for floppy drives,support for VGA, EGA, Hercules and others. Version numberswent from 0.12 straight to 0.95 and 0.96, etc. Soon the codewent around the world from FTP sites in Finland andelsewhere.
c. confrontation & Development
Linus soon met resistance from Andrew Tanenbaum himself, the great teacher who wrote minix. In a letter to Linus,Tannenbaum said:
"We still maintain that to develop a monolithic kernel in 1991 isa fundamental error. Be thankful you're not by my
students. I would not get high marks in a similar design:-) "
(Andrew Tanenbaum to Linus Torvalds)
Linus later admitted that this was the worst period of the development of Linux. Tannenbaum was undoubtedly famousprofessor and you say clearly mattered. But he was wrong in terms of Linux because Linus was a stubborn man who does not allow defeat.
Tannenbaum said, "Linux is old-fashioned."
Was the turn of the younger generation Linux. Backed bystrong Linux community, Linus gave Tannenbaum answer thatseemed most appropriate:
Your job is to be a professor and researcher: That's a hell of a good excuse for some thoughtless minix.
(Linus Torvalds to Andrew Tanenbaum)
And work continued. Soon hundreds of people united to the camp of Linux. And then - thousands. And then - hundreds ofthousands. Linux was not a hacker toy. Aided by a huge amount of programs from project GNU, Linux really was readyto hit the stage. He was licensed with GNU General Public License, thus ensuring that the source code will be available for anyone to copy, learn and change. Students andprogrammers it flew.
Soon intervened and commercial vendors. Linux itself wasfree. What these providers did was to compile various programs and assemble them into a format suitable fordistribution, similar to that of other operating systems withwhich people were accustomed. Red Hat, Caldera, Debianand other companies received a significant response fromusers around the world. The new graphical user interfaces(such as X-windows, KDE, GNOME) Linux distributions have become very popular.
Meanwhile, the amazing things happening with Linux. By PCarchitecture, Linux was ported and many more platforms. Linuxwas forced to work on the PalmPilot - PDA 3Com. Clusteringtechnology allowing a large number of Linux machines beorganized as a single computing environment - parallelcomputer. In April 1996, researchers at the National Laboratory in Los Almos used Linux to run 68 computer asone to simulate waves in a nuclear attack. But unlike othersuper-computers costing a fortune, this decision was quitecheap. Super-computer type "DIY" worth only $ 152,000, including labor (connect 68 computers with cables) -approximately one tenth of the cost of comparable commercialmachine. The maximum speed reached was 19 billionoperations per second, making super-computer Los Almos315th most powerful supercomputer in the world. In this super-computer was quite stable. Three months later still not beenhad to be restarted.
The best thing in Linux today is the fanatics who follow him.Once there is a new hardware, the Linux kernel is adjusted to be able to use it. For example, a few weeks after the appearance of the processor Intel Xeon®, the Linux kernelwas processed and ready for it. The core was adapted forAlpha, Mac, PowerPC and even palmtops, which is difficultachievement comparable to any other operating system. AndLinux continues its journey into the new millennium with the same enthusiasm with which it began on a beautiful day in1991.
As for Linus, he remains an ordinary man. Unlike Bill Gates, he's not a billionaire. After finishing his studies, he moved tothe United States and began working in the corporationTransmeta. Following a highly-secret project, Transmetaprocessor put into production Cruose. Linus was an activemember of the research team. Recently married Tove and is now the proud father of a girl, Amanda Torvalds Patricia(Patricia Amanda Torvalds). But it remains the most loved andmost famous developers of the world to this day.Kompyutardzhiyskite worshiped by communities around the world, Linus is the most popular, so far, the programmer on the planet.
d. A decade later: Linux today
Confirming all warnings and predictions of skeptics Poweredended decade of development. Today, Linux is one of thefastest growing operating system in history. By severaldevoted fanatics in 1991-92 to millions of users at the moment - it is certainly remarkable journey. Large companies"discovered" Linux and pumped millions of dollars into its development, exposing the anti-business myth of the open source movement. Corporation IBM, considered the worst enemy of the hacker community is highlighted with a huge fund for development of open source solutions based on Linux. But what really surprises is continuously growing group ofdevelopers around the world who work with zeal zeal to improve Linux. Efforts of developers are not, as many advocates of the closed code accuse fully sunk into chaos. Setis well designed model of development, sat by several participants. Along with hundreds of developers working onporting various programs under Linux.
Commercial enterprises no longer keep from Linux. With the large number of vendors providing support for Linux-basedproducts to use Linux office technology is no longer a "use at your own risk." The reliability, Linux certainly proved during CIHvirus attacks in 1999 and "Love Letters" a year later when the Linux-based machines showed immunity to damage theseviruses cause. Packages to install Linux by Red Hat receivedhearty response, they become public. And even after the collapse of the dot-com-and in recent years, these companies continue to thrive and grow. With these assurances, manylarge and small companies have embraced Linux based servers and workstations as part of their offices.
Rise of Linux on the desktop machines
What is the biggest complaint against Linux? Perhaps in the past, was the textual interface that frightened many people."The text mode allows complete control" may explain somededicated hackers and users. But for the millions of ordinarypeople, it also means a lot of effort to learn the system.Existing system X-Windows and window managers were notexpected by the users level. Exactly this argument was alwaysinvoked by the hardcore followers of Windows (TM) camp. But things started to change in recent years. The emergence ofprofessional looking desktop environments such as KDE (K Desktop Environment) and GNOME complete the picture. The latest versions of these environments have changed the overall perception of the "friendliness" of Linux to a large extent.Although hardcore users grumble about the loss of purity of the hacker culture, this major change in the attitude of ordinary consumers increase the popularity of Linux.
Linux in the developing world
The rise of Linux and other open source products changed everything. Once Linux can be run on a computer with very littleresources, it has become a viable alternative for users of low-cost computers. Ancient 486 / Pentium computers become part of history in the developed world are still used in developing countries. Powered and let it unfold the full potential of these computers. The use of open source softwarealso expand as the cost of software is a big question. In Asia, Africa and Latin America, Linux seemed like a way to escapethe masses computer enthusiasts. And as evidence of the truly global nature of Linux, in some parts of the world were made tolocal variations. Documentation of Linux now includesdocuments written in almost all major languages ... and alsomany others, such as Vietnamese, for example.
From desktops to supercomputers
When Linus Torvalds first imagined Linux, it was just a hobbyfor hackers. But the modest Intel 386 Linus, which was placedfirst core Linux has come a long way. Most remarkable is itsuse today in large clusters for parallel computing. Let's look atsome examples:
In August 2001, BBC reported that the United States government is planning to make a mega-computer capable of performing more than 13 trillion calculations per second (13.6 TeraFLOPS). The project, called Tetragrid would consist of anetwork linking four central United States superizchisleniya.The four laboratories that collaborate to create Teragrid are: National Center superizchisleniya (NCSA), SuperizchisleniyaCenter in San Diego (SDSC) at the University of California,Argon National Laboratory in Chicago and the CaliforniaInstitute of Technology in Pasadena. In each of these centerswould be a super-computer. Overall it would be a 3000processor operating simultaneously to create Tetragrid. The main technology behind this huge computer would beclustering: technology to connect very weak and cheapprocessors for the creation of a unified computing environment.
Called "Distributed heavyweight device", Teragrid will combine enough computing power to facilitate the solving of complex mathematical and simulation problems ranging fromastronomy and Cancer Research to weather prediction.Packed with 600 TB of storage, Teragrid will be so powerful that a person working with a calculator would need 10 million years to do what Teragrid can do for just a second. The amazing thing is that such a big mega-parallel computer will be managed by Linux. In each of the four centers will run Linuxcluster, and will be connected through the 40 Gb / s optical network.
Evolocity at Lawrence Livermore National Lab
In July 2002, it was reported that Linux NetworX, California-based company began work on Evolocity, powerful Linux-based cluster supercomputer for the National LaboratoryLawrence Livermore (LLNL) in California. This cluster will consist of 962 knots, operating a total of 1920 CPU Intel 2.4 GHz Xeon. With 4 GB DDR SDRAM memory and 120 GB of disk space for each unit, a super-computer will run at a maximum speed of 9.2 TeraFLOPS (FLoating Operations Per Second), which ranks it among the five fastest super-computerin the world. With a lot of cutting edge technology, thissupercomputer will probably bring a breath of fresh air inLLNL, where reigns largest ever supercomputer Cray.
Using Linux as the base system manufacturers Teragrid savedmillions of dollars using cluster technology developed by the dedicated followers of the movement for open sourceworldwide.
The journey continues
Powered journey from hacker to globalization project was more of an evolutionary experience. The project GNU, startedin the early 80's by Richard Stallman, the basis for the development of open source software. Operating system for PCs Minix prof. Andrew Tanenbaum led the study of operating systems from theory to practice. Finally, the endlessenthusiasm of Linus brought Linux into the world. In recent years, hundreds of thousands of members of the global community to raise him and brought him to the glorious place in the annals of the computer revolution. Today, Linux is not just another geeky project a student; it is a global phenomenoncollecting large companies like IBM and millions of people around the world with the spirit of open source software. In the history of computing, it will forever remain as one of the most amazing human achievements.
Penguin Tux: The symbol of Linux
Linux is a symbol of the penguin. Unlike other commercial products including computer operating systems, Linux willhuge, serious character. Tux, a penguin is affectionately called,rather symbolizes the carefree attitude of the whole movement.This cute logo has a very interesting story. At the suggestion ofLinus originally was not chosen any logo for Linux. Linus oncewent to the southern hemisphere on vacation. There he met apenguin, not much different from the current logo of Linux.When he tried to stroke him, the penguin bite him on the arm.This interesting incident led to the selection of a penguin logoLinux later.
f. Some interesting details
Some famous words of Linus :.
Dijkstra probably hates me
(Linus Torvalds, in kernel / sched.c)
"How do I know if it works?'s What beta testers are. I only
I write code. "
(Attributed to Linus Torvalds, somewhere in the postings)
"I'm an idiot .. At least for this [bug] took me five minutes to find him .."
(Reply to Linus Torvalds on a bug report.)
"If you want to travel the world and invite you to speak
different places, just write a Unix operating system. "
>> Besides the fact that Linux has a cool name, could someone explain to me why
>> Should use Linux instead of BSD?
> Do not. That's all. Cool name and that's it. Quite potrudihme
> Find a name that appeals to most people, but
> It has paid off: thousands of people are using linux just to be able
> To say: "OS / 2? Ha !. I've got Linux. What name". 386BSDmade
> Mistake of putting a lot of numbers and weird cuts
> Name and terrified people because the name sounds too
> Their technical.
(Reply Linus Torvalds question for Linux)
> The day people decide it would be better for Linux to be developed by
> Someone else (FSF of May is the natural alternative), I would "abdicate." I do not think
> This is something that people are worried now - I do not seeanything
> To happen in the near future. I have fun doing linux, even though it means
> A little more work, but I have no complaints (few timidreminders
> A patch, which I forgot or I'm not paying attention, but nothing
> Negative to this point).
> I do not understand the above, in the sense that it will give upthe day when
> Anyone complains: I am enough "pachyderm" (Lasu, who(which !?) read over my shoulder
> Commented that "stubborn is closer to the truth") to assumea certain amount of abuse.
> If I had not, I would not stop can develop linux in the day thatTannenbaum took me for a ride.
> What I mean is that even though linux so far was my child,
> I would not have stood in the way of people who want to dosomething even better than him (*).
> (*) Hey, maybe I could apply for a saint-hood from the Pope.Does
> Somebody know what his email-address is? I'm so nice it makes you puke.
(Taken from Linus's reply to someone worried about the future of Linux)
`When you say" I wrote a program that crashed Windows-and"people look at
you blankly and say "Hey, I got those running your operating system, * for free *". '
(From Linus Torvalds)