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Script Kiddie

Script kiddie

In computing, a script kiddie (occasionally script bunny, script kitty or skiddie) is a derogatory term for inexperienced crackers who use scripts and programs developed by others without knowing what they are or how they work for the purpose of compromising computer accounts and files, and for launching attacks on whole computer systems (see DoS). In general, they do not have the ability to write these kinds of programs on their own. Such programs have included WinNuke applications, Back Orifice, and Sub7. Script kiddies, instead of attacking an individual system, often scan thousands of computers looking for vulnerable targets before initiating an attack. The term is also often used as a derogatory moniker for individuals who do not contribute to the development of new security-related programs, especially exploits, but rather benefit from the work of others. This is similar to wardialing and wardriving in which the attacker isn't looking at one specific system, but instead anything that is open and looks interesting. Script kiddies can be a potential aid to more dangerous types of crackers who can encourage and manipulate them into being more destructive. The term is a reference to Linux/Unix scripts, which are small simple-to-use applications that can accomplish a specific task with little more input than the target of the attack. To some however the term expresses considerable contempt, being meant to indicate that they are immature (or unable to realise the equality lesson contained in the somewhat loaded term), and only use "scripts" and programs created by other people, in what is merely simple vandalism.

Script kiddie scene

From around 1995 on, the widespread use of the Internet in the business and home computer field, and the full disclosure movement's policy of disclosing working exploitation tools has led to an enormous growth of the script kiddie scene. Script kiddies often act out of boredom or a desire to 'play war' on the Internet. There are many organised script kiddie groups, who often meet in anonymous chat channels on IRC servers. One example of the work of a script kiddie was the Kournikova Worm in which millions of Microsoft Outlook users received e-mails with the prospect of viewing a picture of tennis star, Anna Kournikova, in an attachment. This virus was similar to the Love Bug, in that it sent itself to all the people in the address books of the recipients.

See also


- Hacker (computer security)
- Security cracking
- Lamer
- Leet Category:Customary categories of people Category:Internet culture Category:Computer security Category:Internet terminology Category:Internet slang



Cracker (computing)

:The black hat is also one of Edward de Bono's Six Thinking Hats. :A black hatter is also a common term for certain groups of people who tend to wear black hats, i.e. Orthodox Jews. A black hat or black-hat hacker (also called a cracker or Dark Side hacker) is a malicious or criminal hacker. The term hacker is also commonly used as a synonym for "black hat hacker". However, in computer jargon, the meaning of "hacker" is much more broad. Usually a Black Hat refers to a person who maintains knowledge of the vulnerabilities and exploits they find as secret for private advantage, not revealing them either to the general public or manufacturer for correction. Many Black Hats promote individual freedom and accessibility over privacy and security. Black Hats may seek to expand holes in systems; any attempts made to patch software are generally to prevent others from also compromising a system they have already obtained secure control over. A Black Hat hacker may have access to 0-day exploits (private software that exploits security vulnerabilities; 0-day exploits have not been distributed to the public). In the most extreme cases, Black Hats may work to cause damage maliciously, and/or make threats to do so for blackmail purposes. Black-hat hacking is the act of compromising the security of a system without permission from an authorized party, usually with the intent of accessing computers connected to the network (the somewhat similar activity of defeating copy prevention devices in software - which may or may not be illegal depending on the laws of the given country - is actually software cracking). The term cracker was coined by Richard Stallman to provide an alternative to abusing the existing word hacker for this meaning. This term's use is limited (as well as "black hat") mostly to some areas of the computer and security field and even there is considered controversial. One group that refers to themselves as hackers consists of skilled computer enthusiasts. The other, and the common usage, refers to people who attempt to gain unauthorized access to computer systems. Many members of the first group attempt to convince people that intruders should be called crackers rather than hackers, but the common usage remains unchanged. Techniques for breaking into systems can vary from using advanced programming skills and social engineering to using semi-automatic software developed by others without understanding how it works. Crackers who rely on the latter technique are often referred to as a script kiddie (unskilled crackers are far more common than highly skilled ones). Common software weaknesses exploited include buffer overflows. The opposite of a black hat hacker is a white hat hacker. The reference to colored hats comes from Hollywood’s use of hats in old black-and-white Western movies to help an audience differentiate between the good guys (white hats) and the bad guys (black hats). The 'hat' terms do not fall under common use. Even inside the computing field they are very controversial. A brown hat hacker is one who thinks before acting or committing a Malice or Nonmalice deed.

See also


- Hacker (computer security)
- White hat
- Grey hat
- Security cracking
- Hacker definition controversy
- Crackers (convicted)
- [http://catb.org/~esr/jargon/html/crackers.html The Jargon File's Entry on Crackers]
- [http://www.wbglinks.net White Hat, Black Hat, Grey Hat links] Category:Computer hacking

Computer system

A computer system consists of a set of hardware and software which processes data in a meaningful way. The personal computer or PC exemplifies a relatively simple computer system. The Internet exemplifies a relatively complex computer system. A computer is a machine that processes data by giving information, and it performs certain operations on the given data and presents the results back. Even the simplest computer classifies as a computer system, because at least two components (hardware and software) have to work together. But the real meaning of "computer system" comes with interconnection. Many computer systems can interconnect, that is, join to become a bigger system. Interconnecting computer systems can prove difficult due to incompatibilities, sometimes between differing hardware and sometimes between different software suites. Designers of individual different computer systems do not necessarily aim to interconnect their product with any other system. But systems administrators can often configure even disparate computers to communicate using a set of rules and constraints known as protocols; these precisely define the "outside view" of the system. This outside view effectively defines the way one system connects with another. If two systems define the same "outside view", they can interconnect and become a larger computer system. This "outside view" usually comes in the form of a standard, that is, a document explaining all of the rules a device or a program must follow. International bodies such as the IETF or IEEE normally set up or endorse such standards. If an individual system obeys all of the rules, systems designers say it "complies with" the standard.

See also


- Computer
- IETF
- IEEE standards
- Legacy system
- Embedded system
- ms:Sistem komputer

WinNuke

The term WinNuke refers to a remote denial-of-service attack (DoS) that affected the Microsoft Windows 95, Microsoft Windows NT and Microsoft Windows 3.1x operating systems. The exploit sent a string of OOB (out of band) data to the target computer on TCP port 139 (NetBIOS), causing it to lock up and display a "blue screen of death", or BSoD. This did not cause any damage to, or change data on, the computer's hard disk, but any unsaved data would be lost. A person under the screenname "_eci" published his Microsoft C source code for the exploit on June 7, 1997. With the source code being widely used and distributed, Microsoft was forced to create security patches, which were released a few weeks later.

See also


- Nuke (computer)

External links


- [http://www.users.nac.net/splat/winnuke/ WinNuke Relief Page]
- [http://techrepublic.com.com/5100-6313-1054537.html Article on a more recent variation of WinNuke (Published: 10/2/02)]
- [http://www.jtan.com/resources/winnuke.html WinNuke Vulnerability Test] category:software category:computer security

Back Orifice

Back Orifice and Back Orifice 2000 (BO2k) are controversial computer programs designed for remote system administration. They enable a user to control a computer running the Microsoft Windows operating system from a remote location. The names are a pun on Microsoft BackOffice Server software.

Back Orifice

Microsoft BackOffice Server Back Orifice was designed with a client-server architecture. A small and unobtrusive server program is installed on one machine, which is remotely manipulated by a client program with a graphical user interface on another computer system. The two components communicate with one another using the TCP and/or UDP network protocols. In a reference to the growing Leet phenomenon, this program commonly runs on port 31337. The program debuted at DEF CON 6 on August 1, 1998. It was the brainchild of Sir Dystic, a member of the U.S. hacker organization CULT OF THE DEAD COW. According to the group, its purpose was to demonstrate the lack of security in Microsoft's operating system Windows 98. Until recently, the versions of Microsoft Windows designed for the public were single-user desktop operating systems, which were never designed to function as secure networking platforms. Despite this, Microsoft marketed Windows as the preferred solution for computer users primarily interested in accessing the Internet. The strategy worked, and Windows enjoyed extremely high market penetration. As a result of the proliferation of Windows systems across the Internet, the operating system was ideally suited for the demonstration of a hacker tool. Although Back Orifice has legitimate purposes, such as remote administration, there are other factors that make it suited for less benign business. The server can hide itself from cursory looks by users of the system. If wrapped inside a Trojan horse, it can be installed without trouble and used as an attack point or just to spy on or harass the unsuspecting user. For those and other reasons, the antivirus industry immediately categorized the tool as malware and appended Back Orifice to their quarantine lists. Despite this fact, it was widely used by script kiddies because of its simple UI and ease of installation.

Back Orifice 2000 (BO2k)

script kiddies Back Orifice was followed by Back Orifice 2000, which debuted on July 10, 1999 at DEF CON 7. The original code was written by Dildog, a member of US hacker group CULT OF THE DEAD COW (cDc). It was the successor to the cDc's Back Orifice remote administration tool, released the previous year. Whereas the original Back Orifice was limited to the Windows 95 and Windows 98 operating systems, BO2k also supports Windows NT. In addition, BO2k was released open source. As of 2005, there is still an active development community of BO2k. As of 2005

See also


- Computer insecurity
- Computer virus
- NetBus
- Sub7

External links


- [http://www.cultdeadcow.com/tools/bo.html Back Orifice official site]
- [http://bo2k.sourceforge.net/ Back Orifice 2000 official site]
- [http://www.everything2.com/index.pl?node_id=769480 BO2k at everything2.com]
- [http://www.iss.net/security_center/advice/Exploits/Ports/31337/default.htm A Security article on the use of port 31337]
- [http://www.cultdeadcow.com/ CULT OF THE DEAD COW] Category:Malware Category:Windows software Category:Computer security Category:Network-related software Category:Cult of the Dead Cow

War dialing

War dialing or wardialing was a technique in the 1980s and '90s by which a computer would repeatedly dial a number (usually to a crowded modem pool) in an attempt to gain access immediately after another user had hung up. The term (and the technique) pre-date the movie WarGames by several years. However, the popularity of the film among computer enthusiasts led to the term being commonly used for what is more precisely known as demon dialing, which figures prominently in the movie. The expansion of accessible internet service provider connectivity since that time more or less rendered the practice obsolete, and today "war dialing" much more frequently refers to demon dialing. An identical technique was sometimes used to get the first call for prizes in radio "call-in" shows, thus leading to the adoption of random "fifth caller," "seventeenth caller" etc. by radio stations to circumvent this practice. The term is also used today by analogy for various sorts of exhaustive brute force attack against an authentication mechanism, such as a password. While a dictionary attack might involve trying each word in a dictionary as the password, wardialing the password would involve trying every possible password.

See also


- demon dialing
- Toneloc, a famous war dialer for DOS.
- war driving

External link


- [http://ssrn.com/abstract=585867 Wargames, Wardialing, Wardriving, and the Emerging Market for Hacker Ethics] category:telephony category:computer security

Linux

:See Linux kernel for the kernel itself. See Linux (washing powder) for the Swiss brand of detergent. See 9885 Linux for the asteroid. asteroid frequently featured sitting, is the official Linux mascot.]] mascot Linux is a computer operating system and its kernel. It is one of the most prominent examples of free software and of open-source development: unlike proprietary operating systems such as Windows and Mac OS, all of its underlying source code is available to the public and anyone can freely use, modify, and redistribute it. In the narrowest sense, the term Linux refers to the Linux kernel, but it is commonly used to describe entire Unix-like operating systems (also known as GNU/Linux) that are based on the Linux kernel combined with libraries and tools from the GNU Project and other sources. Most broadly, a Linux distribution bundles large quantities of application software with the core system, and provides more user-friendly installation and upgrades. 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. Proponents and analysts attribute this success to its vendor independence, low cost, security, and reliability. Linux was originally developed for Intel 386 microprocessors and now supports all popular computer architectures (and several obscure ones). It is deployed in applications ranging from embedded systems (such as mobile phones and personal video recorders) to personal computers to supercomputers.

History

supercomputer project for a free operating-system.]] In 1983, Richard Stallman founded the GNU project, which today provides an essential part of most Linux systems (see also GNU/Linux, below). The goal of GNU was to develop a complete Unix-like operating system composed entirely of free software. By the beginning of the 1990s, GNU had produced or collected nearly all of the necessary components of this system—libraries, compilers, text editors, a Unix-like shell, and other software—except for the lowest level, the kernel. The GNU project began developing their own kernel, the Hurd, in 1990 (after an abandoned attempt called Trix). According to Thomas Bushnell, the initial Hurd architect, their early plan was to adapt the BSD 4.4-Lite kernel and, in hindsight, "It is now perfectly obvious to me that this would have succeeded splendidly and the world would be a very different place today" [http://www.groklaw.net/article.php?story=20050727225542530]. However, due to a lack of cooperation from the Berkeley programmers, Stallman decided instead to use the Mach microkernel, which subsequently proved unexpectedly difficult, and the Hurd's development proceeded slowly. Mach microkernel Meanwhile, in 1991, another kernel—eventually dubbed "Linux"—was begun as a hobby by Finnish university student Linus Torvalds while attending the University of Helsinki. Torvalds originally used Minix, 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 develop a replacement for Minix. Linux started out as a terminal emulator written in IA-32 assembler and C, which was compiled into binary form and booted from a floppy disk so that it would run outside of any operating system. The terminal emulator was running two threads: one for sending and one for receiving characters from the serial port. When Linus needed to read and write files to disk, this task-switching terminal emulator was extended with an entire filesystem handler. After that, it gradually evolved into an entire operating system kernel intended as a foundation for POSIX-compliant systems. The first version of the Linux kernel (0.01) was released to the Internet on September 17, 1991, with the second version following shortly thereafter in October [http://groups.google.com/groups?selm=1991Oct5.054106.4647%40klaava.Helsinki.FI]. Since then, thousands of developers from around the world have participated in the project. Eric S. Raymond's essay The Cathedral and the Bazaar discusses the development model of the Linux kernel and similar software. By the 0.01 release, Linus had implemented enough POSIX system calls to make Linux run the GNU Bash shell; after this bootstrapping procedure, development accelerated rapidly. A computer running Minix was originally necessary in order to configure, compile, and install Linux. Initial versions of Linux also required an operating system to be present in order to boot from a hard disk, but soon there were independent bootloaders, the most well known being lilo. The Linux system quickly surpassed Minix in functionality; Torvalds and other early Linux kernel developers adapted their kernel to work with the GNU components and user-space programs to create a complete, fully functional, free operating system. Today, Torvalds continues to direct the development of the kernel, while other subsystems such as the GNU components are developed separately. The task of producing an integrated system, which combines all of these basic components along with graphical interfaces (such as GNOME or KDE, which in turn are based on the X Window System) and application software, is now performed by Linux distribution vendors / organizations. Tux the penguin is the logo and mascot of Linux (although there are other, less common representations; see OS-tan), based on an image created by Larry Ewing in 1996. The name "Linux" was coined, not by Torvalds, but by Ari Lemmke. Lemmke was working for the Helsinki University of Technology (HUT), located in Espoo near Helsinki, as an administrator of ftp.funet.fi, an FTP server which belongs to the Finnish University and Research Network (FUNET), which has numerous organizations as its members, amongst them the HUT and the University of Helsinki. He was the one to invent the name Linux for the directory from which Torvalds' project was first available for download [http://liw.iki.fi/liw/texts/linux-anecdotes.html]. (The name Linux was derived from Linus' Minix.) The name was later trademarked (see below).

Licensing

The Linux kernel, along with most of the GNU components, is licensed under the GNU General Public License (GPL). The GPL requires that all 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." [http://kde.sw.com.sg/food/linus.html] Other subsystems use other licenses, although all of them share the property of being free/open-source; for example, several libraries use the LGPL (a more-permissive variant of the GPL), and the X Window System uses the permissive (non-copyleft) MIT License. The Linux trademark ([http://assignments.uspto.gov/assignments/q?db=tm&qt=rno&reel=&frame=&sno=&rno=1916230 U.S. Reg No: 1916230]) is owned by Linus Torvalds, registered for "Computer operating system software to facilitate computer use and operation." The licensing of the trademark is now handled by the Linux Mark Institute (LMI). LMI has also sought to enforce the Linux trademark in countries other than the US. In September 2005, Intellectual Property Australia, the trademark regulator in Australia, rejected an application to trademark Linux.

Pronunciation

Linux is commonly pronounced either to rhyme with minix , or to rhyme with my nicks . The first pronunciation is considered more correct, while the second has become popular for sounding more natural in English. Other variations are also possible, but less frequently heard. In 1992, Torvalds explained [http://groups.google.com/groups?selm=1992Apr23.123216.22024%40klaava.Helsinki.FI&output=gplain] (IPA pronunciations added to quote in braces): :"'li' is pronounced with a short [ee] sound: compare prInt, mInImal etc. 'nux' is also short, non-diphthong, like in pUt . 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 [http://www.jx90.com/linux.html audio file] of Torvalds saying "Hello, this is Linus Torvalds, and I pronounce Linux as /linəks/" also exists [http://www.paul.sladen.org/pronunciation/]. Note that in English, "Linux" and "Minix" are usually pronounced with a short /I/ sound that is different from Torvalds's Finland-Swedish pronunciation of these words. See also List of words of disputed pronunciation for a discussion of the various ways "Linux" is pronounced.

Linux and GNU/Linux

Because the GNU libraries and programs, an essential part of nearly all Linux distributions, stem from a long-standing free operating system project that predates the Linux kernel, Richard Stallman and the Free Software Foundation ask that the combined system (regardless of distribution) be referred to as GNU/Linux or a Linux-based GNU system. Torvalds, the creator of the Linux kernel, has said that he finds calling Linux in general GNU/Linux "just ridiculous." Still, some distributions do use this name — notably Debian GNU/Linux — while most people simply refer to the system as Linux. The distinction between Torvalds' kernel and entire Linux-based systems that contain the kernel is a perennial source of confusion, and the naming remains controversial.

Litigation

In March 2003, the SCO Group (SCO) filed a lawsuit against IBM claiming that IBM had contributed some 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 (partially dismissed in July, 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. A few of Novell's press releases seem to demonstrate serious problems with SCO's claims:
- [http://www.novell.com/news/press/archive/2003/06/pr03036.html 2003-May-15] Novell Statement on SCO Contract Amendment (good news for Linux users)
- [http://www.novell.com/news/press/archive/2003/05/pr03033.html 2003-May-28] Novell Challenges SCO Position, Reiterates Support for Linux
- [http://www.novell.com/news/press/pressroom/news_brief/archive/2003/05/pr03022.html 2003-May-30] Novell statement re: SCO press conference allegations
- [http://www.novell.com/news/press/archive/2003/06/pr03036.html 2003-Jun-06] Novell Statement on SCO Contract Amendment
- [http://www.novell.com/news/press/pressroom/news_brief/archive/2003/11/pr03042.html 2003-Nov-18] Novell Statement on SCO claims regarding a non-compete clause in Novell-SCO contracts The most comprehensive coverage of this suit is given by Groklaw.

Distributions

Linux 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 include additional system software and application programs, as well as certain processes to install these systems on a computer. 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 [http://lwn.net/Distributions/]. A typical general-purpose distribution includes the Linux kernel, some GNU libraries and tools, command-line shells, and thousands of application software packages, from office suites and the graphical X Window System to compilers, text editors, and scientific tools. A variety of Linux distribution screenshots can be viewed [http://shots.osdir.com/ here].

Development efforts

[http://www.dwheeler.com/sloc/redhat71-v1/redhat71sloc.html 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 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 dollars) to develop by conventional proprietary means. The source code for the Linux kernel used to be maintained using the software application called BitKeeper but there was a dispute with its openness so now it is maintained via Git, the new directory content manager created by Linus Torvalds himself.

Applications

Git In the past, a user needed significant knowledge of computers in order to install and configure Linux. Because of this, and because of being attracted by access to the internals of the system, Linux users have traditionally tended to be more technologically oriented than users of Microsoft Windows and Mac OS, sometimes revelling in the tag of "hacker" or "geek". This stereotype has been dispelled in recent years by the increased user-friendliness and broad adoption of many Linux distributions. Linux has made considerable gains in server and special-purpose markets, such as image rendering and Web services, and is now making inroads into the high volume desktop market. geek Linux is the cornerstone of the so-called LAMP server-software combination (Linux, Apache, MySQL, Perl/PHP/Python) that 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 Wikipedia. The multi-billion dollar video game industry will see widespread Linux use 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. Linux is also often used in embedded systems. Its low cost makes it particularly useful in set-top boxes and for devices such as the Simputer, a computer aimed mainly at low-income populations in developing nations. In mobile phones, Linux has become a common alternative to the Symbian OS software. In handheld devices, it is an alternative to the Windows CE and Palm OS operating systems. The popular TiVo PVR also uses a customized version of Linux. A large number of network firewalls and routers, including several from Linksys, use Linux internally, taking advantage of its advanced firewalling and routing capabilities. It is also expanding into telecommunications equipment through efforts such as Carrier Grade Linux. Linux is increasingly common as an operating system for supercomputers, most recently on 64-bit AMD Opterons in the Cray XD1. As of June 2005, the 3 fastest supercomputers in the world (as recorded by the Top500) run Linux. Linux is rapidly gaining popularity as a desktop operating system. In desktop environments like GNOME and KDE, Linux may be used with a user interface that is similar to that of Mac OS, Microsoft Windows, other desktop environments, and its traditional Unix-like command line interface. Graphical Linux software exists for almost any area and in some areas there is a greater quality and quantity of software available than for proprietary operating systems.

Usability and market share

Once viewed as an operating system only computer geeks could use, Linux distributions have become user-friendly, with many graphical interfaces and applications. Its market share of desktops is rapidly growing. According to market research company IDC, in 2002, 25% of servers and 2.8% of desktop computers were already running Linux. However, argued advantages of Linux, such as lower cost, fewer security vulnerabilities [http://www.theregister.co.uk/security/security_report_windows_vs_linux/] , and lack of vendor lock-in, have spurred a growing number of high-profile cases of mass adoption of Linux by corporations and governments. The Linux market is among the fastest growing and is projected to exceed $35.7 billion by 2008 [http://www.techweb.com/wire/showArticle.jhtml?articleID=55800522]. Linux and other free software projects have been frequently criticized for not going far enough in terms of ensuring usability, and Linux was once considered more difficult to use than Windows or the Macintosh, although this has changed. Applications running within graphical desktop environments such as GNOME and KDE in Linux are very similar to those running on other operating systems. While some applications cannot be run, there usually exists a replacement that will, sometimes of better quality. A growing number of proprietary software vendors are supporting Linux, and open source development for Linux is also steadily increasing. Additionally, proprietary software for other operating systems may be run through compatibility layers, such as Wine. The area of hardware and services configuration is where user experience is most varied. GUI configuration tools and control panels are available for many system settings and services, but editing of plain-text configuration files is often required. On the command shell, many usability hangups from early Unix days generally remain, such as the difficulty in finding some commands, and the inability to undo many operations such as file deletion. Many older programs with text user interfaces (TUI) have wild inconsistencies between them, but they maintain loyal followings. It used to also be easier to find local technical support for Windows or Mac OS than for Linux in some places. It is worth noting that an operating system's usability is subjective and dependent on the background knowledge and needs of its users. For example, Gentoo Linux, a source-based distribution, is time-consuming to install, but can be more usable for advanced users than stereotypical beginner-friendly distributions, such as Mandriva or Ubuntu. Users might have to switch application software, and there may be fewer options, as in the case of computer games. Equivalents of some specific programs may not be available. However, general applications like spreadsheets, word processors, and browsers are available for Linux in profusion. Most distributions of Linux have two or more means of software installation, and more office and end-user applications now come with an automated installation program. Because of reluctance to change and the fact that many computers still come with Microsoft Windows pre-installed, there has been a slow initial adoption of new desktop operating systems. Linux is past that stage now, with numerous manufacturers installing Linux and many organizations having five or more years experience with Linux - since installation evolved to graphical user interfaces - or Unix, which has been around for decades. Linux is rapidly gaining popularity as a desktop operating system as it is increasingly used in schools and workplaces and more people are becoming familiar with it. Support for certain new and obscure hardware remains an issue. Though some vendors provide device drivers, many device drivers must be developed by volunteers after the release of the product. Often, this development requires reverse engineering of some sort, as certain manufacturers remain secretive and refuse to provide the hardware or firmware specifications for their products. Deliberately non-portable hardware drivers like Winmodems and Winprinters have been a general problem. There have been conflicting studies of Linux's usability and cost in the past. Microsoft-sponsored studies such as those by IDC and Gartner have argued that Linux had a higher total cost of ownership (TCO) than Windows. However, Relevantive, the renowned Berlin-based organization specializing in providing consultation to companies on the usability of software and Web services, concluded that the usability of Linux for a set of desktop-related tasks is "equal to Windows XP." Since then, there have been numerous independent studies that show that a modern Linux desktop using Gnome or KDE is on par with or superior to Microsoft Windows. Linux distributions have been criticized for unpredictable development schedules, thus making enterprise users less comfortable with Linux than they might be with other systems (Marcinkowski, 2003). However, some observers claim that the intervals between Linux distribution releases are no worse, and often better, than the project management "schedule slipping" that occurs with other operating systems and with software systems in general. The large number of choices of Linux distributions can also confuse users and software vendors. The paper [http://www.dwheeler.com/oss_fs_why.html 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 systems, but the process has been made easy in recent years. Many distributions are at least as easy to install as a comparable version of Windows. It is unnecessary to file license numbers and enter them during installation. Also, personal computers that come with Linux distributions already installed are readily available from numerous vendors, including large mainstream vendors like Hewlett-Packard and Dell. The most common method of installing Linux, supported by all major distributions, 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. Some distributions, such as Debian, can be installed from a small set of floppy disks. After a basic system is installed, more software can be added by downloading it from the Internet or using CDs. Other distributions, such as Knoppix, can be run directly from a "live CD" running entirely in RAM, rather than installing it to the hard drive. With this, one boots from the CD and can use Linux without making any modification to the contents of the hard drive. Similarly, some minimal distributions, such as tomsrtbt, can be run directly from as little as 1 floppy disk without needing to change the hard drive contents. Still another mode of installation of Linux is to install on a powerful computer to use as a server and to use ordinary less powerful machines (perhaps without hard drives, and having less memory and slower CPUs) as clients over the network. Clients can boot over the network from the server and display results and pass information to the server where all the applications run. A Linux Terminal Server is a single machine to which many clients can connect this way, so one obtains the benefit of installing Linux on many machines for the cost of installing on one. The clients can be ordinary PCs with the addition of the network bootloader on a drive or network interface controller. Variations on this mode include using local drives and computing power to run applications. The cost savings achieved by using thin clients can be invested in greater computing power or storage on the server. Many distributions also support booting over a network, so an installation on a properly configured machine can be done remotely. Anaconda, one of the more popular installers, is used by Red Hat Linux, Fedora Core and other distributions to simplify the installation process. It is famous for its ability to automatically partition a hard drive using the Disk Druid utility.

Installation on an existing platform

Many distribution companies now are sparing no effort to provide users with advanced, easy and specific installations. Some beginners (especially those familiar with Microsoft Windows and Mac OS) may still feel that making the shift can be hard but many solutions have been created to solve this problem. Some let the user install Linux on top of their current system. Consider WinLinux, for example. After downloading the installer (more than 100MB), the user can install Linux just like any other Windows application. The software provides all the needed features; it is a real Linux distribution. The difference is that it is not necessary for the user to leave Windows, since Linux is installed to the Windows hard-disk partition. A Linux boot loader will boot the Linux system when the PC is restarted and the user chooses to boot Linux. Similar approaches include coLinux. Technology of virtual machines (such as Virtual PC or VMware) also enables Linux to be run inside another OS such as Microsoft Windows. The virtual machine software will simulate an isolated environment onto which the Linux system is installed. After everything is done, the virtual machine can be booted just as if it were an independent computer.

Demonstration

The difficulty in quickly demonstrating Linux on the computer of a potential new user remains still an obstacle, slowing its adoption as a personal computing platform. So-called "live CDs" that simply boot from CD and automatically load the necessary drivers for the user's respective system promise to change that. Linux User Groups or LUGS, still provide the primary face-to-face forum for demonstration of Linux. Commercial exhibitions provide Linux demonstrations to potential new users, especially corporate buyers. Many commercial distributions are hard to install, but with work, allow someone to re-use an old machine to see what the Linux desktop is like. The approach by Knoppix, which runs Linux directly from a CD without disturbing the PC's hard drive, is probably the most successful demonstration tool to date. MEPIS also runs from CD like Knoppix and they both can also be installed onto a PC like any other Linux distribution. Ubuntu also has a separate "Live" version of their distribution which runs from CD. The fastest approach is probably that of Workspot, which uses VNC to provide a free Linux desktop demo online.

Configuration

Configuration of most system wide settings are stored in a single directory called /etc, while user-specific settings are stored in hidden files in the user's home directory. A few programs use a configuration database instead of files. There are a number of ways to change these settings. The easiest way to do this is by using tools provided by distributions such as Debian's debconf, Mandriva's Control Center, or SUSE's YaST. Others, like Linuxconf, Gnome System Tools, and Webmin, are not distribution-specific. There are also many command line utilities for configuring programs. Since nearly all settings are stored in ordinary text files they can be configured by any text editor.

Running Windows applications

There are several ways to run applications written for Microsoft Windows on Linux, with varying levels of success. The popular Wine software, along with the commercial derivatives Crossover Office and Transgaming's Cedega create an application compatibility layer by reimplementing the Windows API inside of Linux. Many Windows programs run on Linux at approximately the same speed using these programs, and in some cases run faster. Since these programs are written without use of any Microsoft code, they do not require a Windows license. Although compatibility is improving, in many cases week-by-week, applications that make use of non-standard programming practices can experience problems. A similar alternative to running Windows applications inside Linux is to use the proprietary Win4Lin software, which converts Microsoft's version of the Windows API to run inside Linux rather than reimplementing it from scratch. Since a legal copy of the Microsoft implementation of the Windows API is needed, use of Win4Lin requires a copy of Windows. A third alternative for running Windows applications within Linux is to use a virtual machine program and run the desired application along with the entire virtual Windows operating system. VMware is a proprietary hardware virtualisation program that can run Windows in this way with near-perfect functionality, however this approach can carry a considerable speed and performance penalty. Full CPU emulators (such as QEMU or the slower counterpart Bochs) can be used, though to run a Windows program these emulators will also require a copy of Windows. Aside from the performance difficulties, virtual machine approaches to running Windows applications cannot integrate Windows programs into the Linux desktop, as they must instead run inside the virtual Windows desktop. A fourth alternative is to run the applications on a Windows machine but use remote access software such as VNC to view it on the Linux desktop. This is a good solution where applications are unable to be migrated, or an item of hardware such as a dongle, custom decoder card, or some USB devices will only run under Windows. At its simplest one or more people needing occasional access to Windows applications can share remote access to a single Windows PC for that purpose using VNC. In a corporate setting essentially the same can be done using a Citrix server, rdesktop to access a Microsoft Terminal Services server, or with NX technology.

Programming on Linux

A number of compilers are available for Linux. The GNU Compiler Collection (GCC) comes with the vast majority of distributions. GCC supports C, C++ and Java among other languages. There are also a number of IDEs available for Linux. Some of the most popular are Anjuta, KDevelop, NetBeans IDE, Glade (actually a user interface designer), Eclipse, the famous Emacs and Vim.

Support

Technical support is provided by commercial suppliers and by other Linux users, usually in online forums, newsgroups and mailing lists. GNU/Linux users are often organised in so called Linux User Groups or abbreviated LUG. The business model of commercial suppliers is generally dependent on charging for support, especially for business users. Companies, which offer a special business version of their distribution, add special support packages and special tools to administrate 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 [http://www.linuxworld.com.au/index.php?id=568003838&fp=16&fpid=0]
- Mackenzie, K. (2004). Linux Torvalds Q&A. Retrieved January 19, 2004 from [http://australianit.news.com.au/articles/0,7204,8407881%5E15841%5E%5Enbv%5E,00.html]
- [http://www.dwheeler.com/sloc More Than a Gigabuck: Estimating GNU/Linux's Size] by David A. Wheeler
- [http://people.debian.org/~jgb/debian-counting Counting potatoes: the size of Debian 2.2] by Jesús M. González-Barahona et al.
- [http://www.dwheeler.com/oss_fs_why.html Why Open Source Software / Free Software (OSS/FS)? Look at the Numbers!] by David A. Wheeler

See also

General


- Access control list
- List of Linux distributions
- Comparison of Linux distributions
- IPodLinux
- Shell account
- LiveCD
- PS2 Linux
- Vmlinux
- Linux consolidation

Lists


- List of file systems
- List of Unix programs
- List of Linux books

Magazines


- Linux Journal
- Linux Magazine
- Linux Format

Videos


-

External links

General
- [http://www.linux.org/ Linux.org] — contains comprehensive information and resources about Linux.
- [http://counter.li.org/ The Linux Counter] — estimates Linux usage around the world
- [http://www.tldp.org/ The Linux Documentation Project]
  - [http://tldp.org/HOWTO/HOWTO-INDEX/categories.html Categorized List of HOWTOs] Distribution related
- [http://eedok.voidofmind.com/linux/chooser.html Distro Quiz] — a test that recommends a distribution based on the answers.
- [http://www.linux.org/dist/ Linux Online] — distributions and FTP Sites (sortable by categories)
- [http://distrowatch.com/ DistroWatch.com] — distribution information & announcements.
- [http://www.linuxiso.org/ Linux ISO] — comprehensive but rather outdated site which has ISO download links for several distributions. Criticism of Linux
- [http://www.microsoft.com/windowsserversystem/facts/default.mspx Microsoft: Get the Facts] — Microsoft site that compares Windows Server software and Linux and comes up with the conclusion that Microsoft software has a lower TCO then Linux.
- Category:Unix Category:Computing platforms Category:Free software operating systems Category:Operating systems als:Linux ja:Linux ko:리눅스 ms:Linux simple:Linux th:ลินุกซ์ zh-min-nan:Linux

Script (computer programming)

Scripting languages (commonly called scripting programming languages or script languages) are computer programming languages initially designed for "scripting" the operations of a computer. Early script languages were often called batch languages or job control languages. A script is more usually interpreted than compiled, but not always. Many such languages are quite sophisticated and have been used to write elaborate programs, which are often still called scripts even though they go well beyond automating simple computer tasks. A script language can be found at almost every level of a computer system. Besides being found at the level of the operating system, they appear in computer games, web applications, word processing documents, network software and more.

Description

Computer languages are created for varying purposes and tasks — different kinds and styles of programming. One common programming task is known as scripting, or connecting diverse pre-existing components to accomplish a new related task. Those languages which are suited to scripting are typically called scripting languages. Many languages for this purpose have common properties: they favor rapid development over efficiency of execution; they are often implemented with interpreters rather than compilers; and they are strong at communication with program components written in other languages. Many scripting languages emerged as tools for executing one-off tasks, particularly in system administration. One way of looking at scripts is as "glue" that puts several components together; thus they are widely used for creating graphical user interfaces or executing a series of commands that might otherwise have to be entered interactively through keyboard at the command prompt. The operating system usually offers some type of scripting language by default, widely known as a shell script language. Scripts are typically stored only in their plain text form (as ASCII) and interpreted, or compiled each time prior to being invoked. Some scripting languages are designed for a specific domain, but often it is possible to write more general programs in that language. In many large-scale projects, a scripting language and a lower level programming language are used together, each lending its particular strengths to solve specific problems. Scripting languages are often designed for interactive use, having many commands that can execute individually, and often have very high level operations (for example, in the classic UNIX shell (sh), most operations are programs themselves). Such high level commands simplify the process of writing code. Programming features such as automatic memory management and bounds checking can be taken for granted. In a 'lower level' or non-scripting language, managing memory and variables and creating data structures tends to consume more programmer effort and lines of code to complete a given task. In some situations this is well worth it for the resulting fine-grained control. The scripter typically has less flexibility to optimize a program for speed or to conserve memory. For the reasons noted above, it is usually faster to program in a scripting language, and script files are typically much smaller than, say, equivalent C program files. The flip side can be a performance penalty: scripting languages, often interpreted, may be significantly slower to execute and may consume more memory when running. In many relevant cases, however, e.g. with small scripts of some tens of lines, the write-time advantage far outweighs the run-time disadvantage. Also, this argument gets stronger with rising programmer salaries and falling hardware costs. However, the boundary between scripting languages and regular programming languages tends to be vague, and is blurring ever more with the emergence of new languages and integrations in this fast-changing area. In some scripting languages, an experienced programmer can accomplish a good deal of optimization if they choose. And in general, it is possible to write a script in any language (including C or assembly language). In most modern systems, the latter case is very seldom recommendable, since one or more suitable script languages is usually available.

Types of scripting languages

Application-specific languages

Many large application programs include an idiomatic scripting language tailored to the needs of the application user. Likewise, many computer game systems use a custom scripting language to express the programmed actions of non-player characters and the game environment. Languages of this sort are designed for a single application and, while they may superficially resemble a specific general-purpose language (e.g. QuakeC, modeled after C) they have custom features which distinguish them.
- ACS
- AutoHotkey
- AutoIt [http://www.autoitscript.com/autoit3/]
- ActionScript
- BlobbieScript [http://www.wocmud.org/Carnage/blobbieScript/]
- GameMonkeyScript
- IRC script
- Lingo
- QuakeC
- UnrealScript
- ZZT-oop
- Emacs Lisp
- AutoLISP
- MEL [http://www.alias.com/eng/products-services/maya/technical_features/api_sdk_mel.shtml]
- HScript

Text processing languages

The processing of text-based records is one of the oldest uses of scripting languages. Many, such as Unix's awk and, later, Perl, were originally designed to aid system administrators in automating tasks that involved Unix text-based configuration and log files. Perl is a special case -- originally intended as a report-generation language, it has grown into a full-fledged applications language in its own right. PHP was originally developed as a specialized language for creating dynamic web content, but is now used by some for general system administration tasks as well.
- Awk
- Perl (but see above)
- Python
- Ruby
- PHP
- Sed
- XSLT
- Request Tracker

Job control languages and shells

Main article: Shell script Another class of scripting languages has grown out of the automation of job control -- starting and controlling the behavior of system programs. Many of these languages' interpreters double as command-line interfaces, such as the Unix shell or the MS-DOS COMMAND.COM. Others, such as AppleScript, add scripting capability to computing environments lacking a command-line interface.
- AppleScript
- AREXX (Amiga REXX)
- bash
- csh
- JCL
- ksh
- MS-DOS batch
- REXX
- sh

General-purpose dynamic languages

Some languages, such as Perl, have begun as scripting languages but developed into programming languages suitable for broader purposes. Other similar languages -- frequently interpreted, memory-managed, dynamic -- have been described as "scripting languages" for these similarities, even if they are more commonly used for applications programming.
- APL
- ColdFusion
- Dylan
- Jython
- Lasso
- Perl
- PHP
- Pike
- Python
- Ruby
- Scheme
- Command Pro
- xBASICx
- FAITH
- Sleep
- Smalltalk
- Aloe

Extension/embeddable languages

A small number of languages have been designed for the purpose of replacing application-specific scripting languages, by being embeddable in application programs. The application programmer (working in C or another systems language) includes "hooks" where the scripting language can control the application. These languages serve the same purpose as application-specific extension languages, but with the advantage of allowing some transfer of skills from application to application.
- ECMAScript a.k.a. ActionScript, DMDScript, JavaScript, JScript
- Guile
- ICI
- Lua
- Sleep
- Tcl (Tool command language) JavaScript began as and primarily still is a language for scripting inside of web browsers, however, the standardization of the language as ECMAScript has made it popular as a general purpose embeddable language. Expect is one of the first extensions of Tcl, and was widely used for controlling terminal-driven tools such telnet, ssh, and ftp.

Others


- BeanShell (scripting for Java)
- Brain
- CobolScript
- Ch (C/C++ interpreter)
- HyperTalk
- E
- Escapade (server side scripting)
- Euphoria
- F-Script
- Groovy
- Io
- KiXtart
- LoadRunner
- mIRC script
- Miva
- Mondrian
- MUMPS (M)
- NWscript
- Object REXX
- Pliant
- REBOL
- ScriptBasic
- Scriptol
- Shorthand Language
- Simkin
- Squirrel
- StepTalk
- UserTalk
- VBScript
- Visual DialogScript

See also


- Domain-specific programming language LoadRunner (from Mercury Interactive Corp) uses ANSI C (or Java, or Visual Basic) as scripting language

External links


- [http://merd.sourceforge.net/pixel/language-study/scripting-language/ A study of the Script-Oriented Programming (SOP) suitability of selected languages] – from The Scriptometer.
- [http://www.hotscripts.com Hotscripts.com] -A collection of many scripts written in an assortment of languages
- ja:スクリプト言語

Internet

:For the more general networking concept, see internetworking. The Internet, or simply the Net, is the worldwide system of interconnected computer networks which makes information stored on it accessible. This information is transmitted by packet switching using a standardized Internet Protocol (IP) and many other protocols. It is made up of thousands of smaller commercial, academic, domestic and government networks. It carries various information and services, such as electronic mail, online chat, and the interlinked web pages and other documents of the World Wide Web.

Creation of the Internet

During the 1950s, several communications researchers realized that there was a need to allow general communication between users of various computers and communications networks. This led to research into decentralized networks, queuing theory, and packet switching. The subsequent creation of ARPANET in the United States in turn catalyzed a wave of technical developments that made it the basis for the development of the Internet. Contrary to popular myth, the DoD did not create the ARPANET so that they could communicate to the US Government after a nuclear war. The first TCP/IP wide area network was operational in 1984 when the United States' National Science Foundation (NSF) constructed a university network backbone that would later become the NSFNet. It was then followed by the opening of the network to commercial interests in 1995. Important separate networks that offered gateways into, then later merged into the Internet include Usenet, Bitnet and the various commercial and educational X.25 networks such as Compuserve and JANET. The ability of TCP/IP to work over these pre-existing communication networks allowed for a great ease of growth. Use of Internet as a phrase to describe a single global TCP/IP network originated around this time. The collective network gained a public face in the 1990s. In August 1991 CERN in Switzerland publicized the new World Wide Web project, two years after Tim Berners-Lee had begun creating HTML, HTTP and the first few web pages at CERN in Switzerland. In 1993 the Mosaic web browser version 1.0 was released, and by late 1994 there was growing public interest in the previously academic/technical Internet. By 1996 the word "Internet" was common public currency, but it referred almost entirely to the World Wide Web. Meanwhile, over the course of the decade, the Internet successfully accommodated the majority of previously existing public computer networks (although some networks such as FidoNet have remained separate). This growth is often attributed to the lack of central administration, which allows organic growth of the network, as well as the non-proprietary open nature of the Internet protocols, which encourages vendor interoperability and prevents any one company from exerting too much control over the network.

Today's Internet

FidoNets, FTP client, and Telnet client]] Apart from the complex physical connections that make up its infrastructure, the Internet is held together by bi- or multi-lateral commercial contracts (for example peering agreements) and by technical specifications or protocols that describe how to exchange data over the network. Indeed, the Internet is essentially defined by its interconnections and routing policies. In an often-cited, if perhaps gratuitously mathematical definition, Seth Breidbart once described the Internet as "the largest equivalence class in the reflexive, transitive, symmetric closure of the relationship 'can be reached by an IP packet from'". Unlike older communications systems, the Internet protocol suite was deliberately designed to be independent of the underlying physical medium. Any communications network, wired or wireless, that can carry two-way digital data can carry Internet traffic. Thus, Internet packets flow through wired networks like copper wire, coaxial cable, and fiber optic; and through wireless networks like Wi-Fi. Together, all these networks, sharing the same high-level protocols, form the Internet. The Internet protocols originate from discussions within the Internet Engineering Task Force (IETF) and its working groups, which are open to public participation and review. These committees produce documents that are known as Request for Comments documents (RFCs). Some RFCs are raised to the status of Internet Standard by the Internet Architecture Board (IAB). Some of the most used protocols in the Internet protocol suite are IP, TCP, UDP, DNS, PPP, SLIP, ICMP, POP3, IMAP, SMTP, HTTP, HTTPS, SSH, Telnet, FTP, LDAP, SSL, and TLS. Some of the popular services on the Internet that make use of these protocols are e-mail, Usenet newsgroups, file sharing, Instant Messenger, the World Wide Web, Gopher, session access, WAIS, finger, IRC, MUDs, and MUSHs. Of these, e-mail and the World Wide Web are clearly the most used, and many other services are built upon them, such as mailing lists and blogs. The Internet makes it possible to provide real-time services such as Internet radio and webcasts that can be accessed from anywhere in the world. Some other popular services of the Internet were not created this way, but were originally based on proprietary systems. These include IRC, ICQ, AIM, and Gnutella. There have been many analyses of the Internet and its structure. For example, it has been determined that the Internet IP routing structure and hypertext links of the World Wide Web are examples of scale-free networks. Similar to how the commercial Internet providers connect via Internet exchange points, research networks tend to interconnect into large subnetworks such as:
- GEANT
- Internet2
- GLORIAD These in turn are built around relatively smaller networks. See also the list of academic computer network organizations In network schematic diagrams, the Internet is often represented by a cloud symbol, into and out of which network communications can pass.

Internet culture

The Internet is also having a profound impact on work, leisure, knowledge and worldviews. worldviews]]

ICANN

The Internet Corporation for Assigned Names and Numbers (ICANN) is the authority that coordinates the assignment of unique identifiers on the Internet, including domain names, Internet protocol addresses, and protocol port and parameter numbers. A globally unified namespace (i.e., a system of names in which there is one and only one holder of each name) is essential for the Internet to function. ICANN is headquartered in Marina del Rey, California, but is overseen by an international board of directors drawn from across the Internet technical, business, academic, and non-commercial communities. The US government continues to have a privileged role in approving changes to the root zone file that lies at the heart of the domain name system. Because the Internet is a distributed network comprising many voluntarily interconnected networks, the Internet, as such, has no governing body. ICANN's role in coordinating the assignment of unique identifiers distinguishes it as perhaps the only central coordinating body on the global Internet, but the scope of its authority extends only to the Internet's systems of domain names, Internet protocol addresses, and protocol port and parameter numbers.

The World Wide Web

Through keyword-driven Internet research using search engines like Google, millions worldwide have easy, instant access to a vast and diverse amount of online information. Compared to encyclopedias and traditional libraries, the World Wide Web has enabled a sudden and extreme decentralization of information and data. Some companies and individuals have adopted the use of 'weblogs' or blogs, which are largely used as easily-updatable online diaries. Some commercial organizations encourage staff to fill them with advice on their areas of specialization in the hope that visitors will be impressed by the expert knowledge and free information, and be attracted to the corporation as a result. One example of this practice is Microsoft, via whose product developers publish their personal blogs in order to pique the public's interest in their work. For more information on the distinction between the World Wide Web and the Internet itself — as in everyday use the two are sometimes confused — see Dark internet where this is discussed in more detail.

Remote access

The Internet allows computer users to connect to other computers and information stores easily, wherever they may be across the world. They may do this with or without the use of security, authentication and encryption technologies, depending on the requirements. This is encouraging new ways of working from home, collaboration and information sharing in many industries. An accountant sitting at home can audit the books of a company based in another country, on a server situated in a third country that is remotely maintained by IT specialists in a fourth. These accounts could have been created by home-working book-keepers, in other remote locations, based on information e-mailed to them from offices all over the world. Some of these things were possible before the widespread use of the Internet, but the cost of private, leased lines would have made many of them infeasible in practice. An office worker away from his or her desk, perhaps the other side of the world on a business trip or a holiday, can open a remote desktop session into his or her normal office PC using a secure Virtual Private Network (VPN) connection via the Internet. This gives him or her complete access to all their normal files and data, including e-mail and other applications, while they are away.

Collaboration

This low-cost and nearly instantaneous sharing of ideas, knowledge and skills has revolutionized some, and given rise to whole new, areas of human activity. One example of this is the collaborative development and distribution of Free/Libre/Open-Source Software (FLOSS) such as Linux, Mozilla and OpenOffice.org. See Collaborative software.

File-sharing

A computer file can be e-mailed to customers, colleagues and friends as an attachment. It can be uploaded to a website or FTP server for easy download by others. It can be put into a "shared location" or onto a file server for instant use by colleagues. The load of bulk downloads to many users can be eased by the use of "mirror" servers or peer-to-peer networking. In any of these cases, access to the file may be controlled by user authentication; the transit of the file over the Internet may be obscured by encryption and money may change hands before or after access to the file is given. The price can be paid by the remote charging of funds from, for example a credit card whose details are also passed - hopefully fully encrypted - across the Internet. The origin and authenticity of the file received may be checked by digital signatures or by MD5 message digests. These simple features of the Internet, over a world-wide basis, are changing the basis for the production, sale and distribution of many types of product, wherever they can be reduced to a computer file for transmission. This includes all manner of office documents, publications, software products, music, photography, video, animations, graphics and the other arts. This in turn is causing seismic shifts in each of the existing industry associations, such as the RIAA and MPAA, that previously controlled the production and distribution of these products.

Streaming media and VoIP

Many existing radio and television broadcasters have provided Internet 'feeds' of their live audio and video streams (for example, the BBC). They have been joined by a range of pure Internet 'broadcasters' who never had on-air licences. This means that an Internet-connected device, such as a computer or something more specific, can be used to access on-line media in much the same way as was previously possible only with a TV or radio receiver. The range of material is much wider, from pornography to highly specialised technical web-casts. The simplest equipment can allow anybody, with little censorship or licencing control, to broadcast on a worldwide basis. Time-shift viewing or listening is not a problem as the BBC have shown with their Preview, Classic Clips and Listen Again features. Web-cams can be seen as an even lower-budget extension of this phenomenon. In this case the picture may update only slowly - perhaps once every few seconds or slower, but Internet users can watch animals around an African waterhole, ships in the Panama Canal or the traffic at a local roundabout live and in real time. Video chat rooms, video conferencing, and remote controllable webcams have become popular. Some people install webcams in their bedrooms that can be accessed by other voyeurs, often with two-way sound. VoIP stands for Voice over IP, where IP refers to the Internet Protocol that underlies all Internet communication. This phenomenon began as an optional two-way voice extension to some of the Instant Messaging systems that took off around the turn of the millennium. In recent years many people and organizations have made VoIP systems as easy to use and as convenient as a normal telephone. The benefit is that, as the actual voice traffic is carried by the Internet, VoIP is free or costs much less than an actual telephone call, especially over long distances and especially for those with always-on ADSL or DSL Internet connections anyway. The disadvantages are that it is still difficult to initiate a call with someone, unless they also have a VoIP phone or are at their computer and that there are still several competing standards that are mitigating against universal acceptance. In all of these cases, existing large organisations, that have grown accustomed to regular incomes for their services, are finding increased competition in their service areas, coming directly from the Internet. While newcomers strive to make these inroads, the traditional industries are having to adapt, adopt, complain or suffer. Meanwhile the consumer in each case most probably benefits from the increased range of services and possible price reductions. Some worry about censorship and control while others see a continuing globalisation of culture and norms.

Language

Main article: English on the Internet The most prevalent language for communication on the Internet is English. This may be due to the Internet's origins or to the growing role of English as an international language. It may also be related to the poor capability of early computers to handle characters other than those in the basic Latin alphabet (see Unicode). After English (32 % of web visitors) the most-requested languages on the world wide web are Chinese 13 %, Japanese 8 %, Spanish 6 %, German 6 % and French 4 %. (From [http://www.internetworldstats.com/stats7.htm Internet World Stats]) By continent, 33 % of the world's Internet users are based in Asia, 29 % in Europe and 23 % in North America.[http://www.internetworldstats.com/stats.htm] The Internet's technologies have developed enough in recent years that good facilities are available for development and communication in most widely used languages. However, some glitches such as mojibake still remain.

Cultural awareness

From a cultural awareness perspective, the Internet has been both an advantage and a liability. For people who are interested in other cultures it provides a significant amount of information and an interactivity that would be unavailable otherwise. However, for people who are not interested in other cultures there is some evidence indicating that the Internet enables them to avoid contact to a greater degree than ever before.

Censorship

Some countries, such as Iran and the People's Republic of China, restrict what people in their countries can see on the Internet, especially unwanted political and religious content. In the Western world, it is Germany that has the highest rate of censorship. Internet Service Providers are required by law to block some sites that contain child pornography or Nazi or Islamist propaganda. Censorship is sometimes done through government sponsored censoring filters, or by means of law or culture, making the propagation of targeted materials extremely hard. At the moment most Internet content is available regardless of where one is in the world, so long as one has the means of connecting to it.

Internet access

Germany Common methods of home access include dial-up, landline broadband (over coaxial cable, fiber optic or copper wires), Wi-Fi, satellite and cell phones. Public places to use the Internet include libraries and Internet cafes, where computers with Internet connections are available. There are also Internet access points in many public places like airport halls, in some cases just for brief use while standing. Various terms are used, such as "public Internet kiosk", "public access terminal", and "Web payphone". Many hotels now also have public terminals, though these are usually fee based. Wi-Fi provides wireless access to computer networks, and therefore can do so to the Internet itself. Hotspots providing such access include Wi-Fi-cafes, where a would-be user needs to bring their own wireless-enabled devices such as a laptop or PDA. These services may be free to all, free to customers only, or fee-based. A hotspot need not be limited to a confined location. The whole campus or park, or even the entire city can be enabled. Grassroots efforts have led to wireless community networks. Apart from Wi-Fi, there have been experiments with proprietary mobile wireless networks like Ricochet, various high-speed data services over cellular or mobile phone networks, and fixed wireless services. These services have not enjoyed widespread success due to their high cost of deployment, which is passed on to users in high usage fees. New wireless technologies such as WiMAX have the potential to alleviate these concerns and enable simple and cost effective deployment of metropolitan area networks covering large, urban areas. There is a growing trend towards wireless mesh networks, which offer a decentralized and redundant infrastructure and are often considered the future of the Internet. Broadband access over power lines was approved in 2004 in the United States in the face of stiff resistance from the amateur radio community. The problem with modulating a carrier signal onto power lines is that an above-ground power line can act as a giant antenna and jam long-distance radio frequencies used by amateurs, seafarers and others. Countries where Internet access is available to a majority of the population include Germany, India, China, Chile, Iceland, Finland, Sweden, Greece, Italy, Australia, Denmark, the United States, Canada, the United Kingdom, The Netherlands, Japan, Singapore, Taiwan, Thailand, South Korea and Norway. The use of the Internet around the world has been growing rapidly over the last decade, although the growth rate seems to have slowed somewhat after 2000. The phase of rapid growth is ending in industrialized countries, as usage becomes ubiquitous there, but the spread continues in Africa, Latin America, the Caribbean and the Middle East. However, there are still problems for many. ADSL and other broadband access are rare or nonexistent in most developing countries. Even in developed countries, high prices, mediocre performance and access restrictions often limit its uptake. Within individual countries, wide differences may exist between larger cities (often having multiple providers of broadband access) and some rural areas, where no broadband access may be available at all. The expansion of the availability of Internet access is a way to bridge the so-called digital divide.

Capitalization conventions

In formal usage, Internet is traditionally written with a capital first letter. The Internet Society, the Internet Engineering Task Force, the Internet Corporation for Assigned Names and Numbers, the World Wide Web Consortium, and several other Internet-related organizations all use this convention in their publications. In English grammar, proper nouns are capitalized. Most newspapers, newswires, periodicals, and technical journals also capitalize the term. Examples include the New York Times, the Associated Press, Time, The Times of India, Hindustan Times and Communications of the ACM. In other cases, the first letter is often written small (internet), and many people are not aware of any convention of using a capital letter. Some argue that internet is the correct form. Since 2000, a significant number of publications have switched to using internet. Among them are The Economist, the Financial Times, the London Times, and the Sydney Morning Herald. As of 2005, most publications using internet appear to be located outside of North America although one American news source, Wired News, has adopted the lowercase spelling.

Leisure

The Internet has been a major source of leisure since before the World Wide Web, with entertaining social experiments such as MOOs being conducted on university servers, and humor-related USENET groups receiving much of the main traffic. Today, many Internet forums have sections devoted to neta; short cartoons in the form of Flash movies are also popular. The