Wikipedia is a multilingual "copyleft" encyclopedia designed to be read and edited by anyone. It is collaboratively edited and maintained by thousands of users via wiki software, and is hosted and supported by the non-profit Wikimedia Foundation. In addition to typical encyclopedia entries, Wikipedia includes information more often associated with almanacs, gazetteers, and specialist magazines, as well as coverage of current events.
There are three essential characteristics of the Wikipedia project, which together define its niche on the World Wide Web:
- It is, or aims to become, primarily an encyclopedia.
- It is a wiki, in that it can be edited by anyone (except for blocked users, and excluding protected pages).
- It is free content, and uses the copyleft GNU Free Documentation License.
- If you wish to become a Wikipedia contributor, please take a look at the page entitled Welcome, newcomers.
Free content license
All original material contributed to Wikipedia is deemed to be free content under the GNU Free Documentation License, meaning that it may be freely used, freely edited, freely copied and freely redistributed subject to the restrictions of that license.
Anyone who wishes to use Wikipedia'Free_content" title ="Free content">free content may at any time download a nearly-current version of the entire article database to use for any purpose, within the terms of the GFDL. 
Editable by everyone
Wikipedia's content is created by its users. Any visitor to Wikipedia can edit its articles, and many do. Pages are always subject to editing, so no article is ever finished. As such, Wikipedia is subject to some unique "hardships" . It has "self-healing" systems in place to deal with these challenges, and even a page designed to explain them .
One pertinent issue on Wikipedia is "vandalism": silly or offensive edits of the site'Sarah_Lane" title ="Sarah Lane">Sarah Lane, presenter of "Sarah's Blog Report", part of The Screen Savers TV program on TechTV, "vandalized" the Wikipedia page on monkeypox live on air  - leading to a surge of vandalism on that page by viewers of the TV show. Lane later wrote that: "Although this excites me in its ease and simplicity, it's a little frightening. I mean, what if I had instead written 'My boss is a big fat **** and his phone number is ****'? Sure, somebody would delete it, but this calls for some seriously dedicated moderators." 
"Because Wikipedia is a radically free, open project, it attracts an anarchistic element," Larry Sanger admitted to Wired News. "Fortunately, most of us are willing to take a definite stand against vandalism ... and to get rid of it instantly." 
- "Recent research by a team from IBM found that most vandalism suffered by Wikipedia had been repaired within five minutes. 'We were surprised at how often we found vandalism, and then surprised again at how fast it was fixed,'Cambridge" title ="Cambridge">Cambridge, Mass." 
Wikipedia began as an English language project on January 15, 2001, and soon gained its first other language, French, on March 23, 2001. There has since been a great deal of effort devoted to making it multilingual, and it currently contains over 400,000 articles in English and over 700,000 in other languages (as of November 2004 ).
Wikipedia was created as an editor-free offshoot of Nupedia, a free encyclopedia project founded by Jimmy Wales. Larry Sanger was employed by Wales to work on Nupedia as the editor-in-chief and later worked on Wikipedia, and was closely involved in setting up the project and establishing the policy framework. He had considerable influence on the direction of the project during his tenure, until he left the project in February 2002. Wales remains actively involved to this day, contributing both time and resources to the project, and is a board member of the Wikimedia Foundation which now oversees the project. There is no editor-in-chief, as such, and no paid employees. Instead, the project relies on the contributions of many thousands of volunteers (referred to as Wikipedians).
On September 20, 2004, Wikipedia reached one million articles  in 105 languages, and received a flurry of related attention in the press. The one millionth article was published in the Hebrew language Wikipedia, and discusses the flag of Kazakhstan .
For a more detailed history of the project, see History of Wikipedia.
Known applications of the idea of collecting all of the world'Library_of_Alexandria" title ="Library of Alexandria">Library of Alexandria and Pergamon. The modern notion of the general purpose, widely distributed, printed encyclopedia dates from shortly before Denis Diderot and the 18th century encyclopedists.
The idea of using automated machinery beyond the printing press to build a more useful encyclopedia can be traced to H. G. Wells' short story World Brain (1937) and Vannevar Bush'Microfilm" title ="Microfilm">microfilm based Memex in As We May Think (1945). An important milestone along this path is also Ted Nelson'Project_Xanadu" title ="Project Xanadu">Project Xanadu (1960).
With the development of the Internet, many people attempted to develop Internet encyclopedia projects. Free software exponent Richard Stallman articulated the usefulness of a "Free Universal Encyclopedia and Learning Resource" in 1999. He described Wikipedia'Free_Software_Foundation" title ="Free Software Foundation">Free Software Foundation encourages people "to visit and contribute to the site". One never-realized predecessor was the Interpedia, which Robert McHenry has linked conceptually to Wikipedia.
Wikipedia's participants (Wikipedians) commonly follow, and enforce, a few basic policies.
- Because there are potentially a huge variety of participants of all ideologies and nationalities Wikipedia is committed to making its articles as unbiased as possible. There has been criticism that the shared systemic bias of participants can color the neutrality of an article — see "Neutral Point Of View", below. According to advocates of the NPOV policy, the aim is not to write articles from a single objective point of view, but rather, to fairly present all views on an issue, attributed to their adherents in a neutral way. However, establishing a consensus on what views should be thus attributed can require much heated discussion and debate, and at any rate the attribution never extends to every single statement within an article. Thus, some people have claimed that NPOV is more of an ideology than an actual policy.
- Because there is no explicit peer review for content submitted to Wikipedia, submissions must be verifiable by readers and other contributors; unverifiable information, or facts newly discovered that have not been published elsewhere (and therefore cannot be qualified by "according to source, ..."), are not welcome. See "No Original Research", below.
- There are a number of important style conventions, particularly with respect to article naming; for example, when several names exist, the most common one in the respective Wikipedia language is preferred.
- Wikipedians use "talk" pages or other "out of band" methods to discuss changes to articles, rather than discussing the changes within the articles themselves. This marked a break from other wikis of the time, such as Ward Cunningham'WikiWiki" title ="WikiWiki">WikiWiki.
- There are a number of kinds of entries which are generally discouraged, because they do not, strictly speaking, constitute encyclopedia articles. For example, Wikipedia entries are not dictionary definitions, and the wholesale addition of source material such as the text of laws and speeches is generally frowned upon. However, some of Wikipedia'Wiktionary" title ="Wiktionary">Wiktionary and Wikisource, are designed to be repositories for many alternative forms of reference material that do not fit well into Wikipedia.
- There are a variety of sometimes contradictory rules, guidelines, policies, and common practices that have been proposed and which have varying amounts of support within the Wikipedia community. When these proposed rules are violated, the community decides on a case-by-case basis whether they should be more strictly enforced or not.
Neutral point of view
Wikipedia is grounded in the idea that all of its articles need to be written from a neutral point of view. The neutral point of view attempts to present ideas and facts in such a fashion that both supporters and opponents can agree. Of course, 100% agreement is not possible; there are ideologues in the world who will not concede to any presentation other than a forceful statement of their own point of view. But Wikipedia seeks a type of writing that is agreeable to essentially rational people who may differ on particular points. According to Jimbo Wales:
- Perhaps the easiest way to make your writing more encyclopedic, is to write about what people believe, rather than what is so. If this strikes you as somehow subjectivist or collectivist or imperialist, then ask me about it, because I think that you are just mistaken. What people believe is a matter of their perception of fact, and we can present that quite easily from the neutral point of view.
The neutral point of view policy states that one should write articles without bias, representing all views fairly. However, like all collaborative projects, Wikipedia has a built-in bias derived from the demographic make-up of its participants. In Wikipedia's case, this manifests itself in a tendency for contributors to create articles that relate to the interests of computer-literate white-collar North Americans and Europeans. An example of this effect can be seen by comparing the large article on Babylon 5 (an American science fiction television series) to the article on the Congo Civil War which, despite being possibly the largest conflict since World War II contains much less information. Note also that most of the Babylon 5 information is actually in other articles on specific alien races, planets, minor characters, et cetera.
This bias has few defenders on Wikipedia. The presence of articles written from an exclusively U.S. point of view is largely a reflection of the fact that there are many Americans working on the project, which in turn is merely a reflection of the fact that so many Americans are online. Greater diversity can be achieved by active collaboration from people outside of the United States, of whom there are many.
No original research
Another grounding principle of Wikipedia is that it is not a place to contribute or look for research that has not yet been published elsewhere. This helps avoid arguments about new untested theories and claims, and limits the contribution of observations and claims which are unverifiable by others.
Wikipedia's utility as a reference work has been questioned. The lack of authority and accountability are considered disqualifying factors by some people. For example, librarian Philip Bradley acknowledged in an interview with The Guardian that the concept behind the site was in theory a "lovely idea", but that he would not use it in practice and is "not aware of a single librarian who would. The main problem is the lack of authority. With printed publications, the publishers have to ensure that their data is reliable, as their livelihood depends on it. But with something like this, all that goes out the window." People supporting the idea of Wikipedia counter these arguments by saying that Wikipedia is a more independent source than most traditional encyclopedias and that the reliability is potentially greater than that of a traditional source, since errors can be corrected immediately.
Wikipedia'Systemic_bias" title ="Systemic bias">systemic bias of covering some topics in much greater depth than others is also considered significant, something that even the site's proponents admit. In an interview with The Guardian, the executive team of Encyclop√¶dia Britannica noted that "people write of things they're interested in, and so many subjects don'Hurricane_Frances" title ="Hurricane Frances">Hurricane Frances is five times the length of that on Chinese art, and the entry on Coronation Street is twice as long as the article on Tony Blair." In reply, a user on the Wikipedia discussion board noted that the Wikipedia entry on Tony Blair still was several times longer than the corresponding entry in Encyclop√¶dia Britannica. It is also noted that Wikipedia tends to cover topics that might not be included at all in a print encyclopedia.
A common Wikipedia maxim is "Out of mediocrity, excellence." The site founder admits that the variation in quality between different articles and topics is significant, but considers the average quality "pretty good", and getting better by the day. The "competing" Encyclop√¶dia Britannica claims it does not feel threatened. "The premise of Wikipedia is that continuous improvement will lead to perfection; that premise is completely unproven," said the reference work's executive editor, Ted Pappas, to The Guardian. It should be noted, however, that Wikipedia articles have been referenced in enhanced perspectives provided on-line in the journal Science, one of the most prestigious (and unmercifully selective) scientific publications in the world. The first of these perspectives to provide a hyperlink to Wikipedia was "A White Collar Protein Senses Blue Light", by Hartmut Linden, in the August 2, 2002 issue. Since then, dozens of enhanced perspectives have provided hyperlinks to Wikipedia. A search on "Wikipedia" in Science's web site  turns up 42 instances as of December 4, 2004, with the perspective "The Maser at 50", by Ronald L. Walsworth, as the latest in that date range.
Much of the Internet community considers Wikipedia an excellent source of information, but it is also often said that one of its failings is that its community is prone to incivility and that some people with administrative powers abuse them. While the process is democratic regarding matters such as deletion, the observed reality in some other debates (for example, criteria for deletion, whether or not an account is one user masquerading as another) is that some users have vastly more influence than others, often for no reason other than having been a contributor for longer. There are also well-documented (though infrequent) cases of adminstrators abusing their powers to "bully" other users.
Finally, by containing a large number of internally linked pages, it receives high rankings from Google. This can also result in high rankings for the often identical Wikipedia mirrors. This makes it more likely that web searches will return identical results.
(See also the section of external links to reviews, endorsements, criticisms, and discussion of Wikipedia, below.)
Software and hardware
The software that originally ran Wikipedia was UseModWiki, written by Clifford Adams ("Phase I"). At first it required CamelCase for links; soon it was also possible to use the current linking method that uses double brackets. In January 2002, Wikipedia began running on a PHP wiki engine, which used an underlying MySQL database, added many features (and abolished the behaviour of CamelCase words automatically becoming links), and was specifically written for the Wikipedia project by Magnus Manske ("Phase II"). After a while, the site started to slow down to such an extent that editing became almost impossible. Several rounds of modifications to the software provided only temporary relief. Then Lee Daniel Crocker rewrote the software from scratch. The new version, a major improvement, has been running since July 2002. This "Phase III" software is now called MediaWiki, and is used by many other wiki projects. Brion Vibber has since taken the lead in fixing bugs and tuning the database for performance.
In late 2003, server outages began to seriously diminish the productivity of Wikipedia contributors. Many reported difficulty editing articles as a result of time-outs and severe slowness. This was due to congestion on the single server that was running all the Wikipedias at the time.
As of June 2004, the project runs on nine dedicated servers, located in Florida. This new configuration includes a single database server and four web servers, all running Fedora Core. The web servers serve pages as requested, performing page rendering for all the Wikipedias. To increase speed further, rendered pages for anonymous users are cached in a filesystem until invalidated, allowing page rendering to be skipped entirely for most common page accesses. Cached requests are served by two Squid servers; the new servers are linked via two file system NFS servers (one primary and one backup — the primary NFS server is currently also the email server).
As of 2004, Wikipedia has many editions. Major ones are:
- Chinese Wikipedia (16,000 articles)
- Dutch Wikipedia (38,000)
- English Wikipedia (400,000)
- French Wikipedia (60,000)
- German Wikipedia (170,000)
- Hebrew Wikipedia (12,000)
- Italian Wikipedia (26,000)
- Polish Wikipedia (46,000)
- Japanese Wikipedia (78,000)
- Portuguese Wikipedia (24,000)
- Swedish Wikipedia (50,000)
- Spanish Wikipedia (33,000)
See  for the complete list.
The number of articles is as of October 2004. See  for the complete table of the size of each edition.
Wikipedia has the following sister projects, part of the Wikimedia family:
- Wiktionary, a free dictionary project
- Wikibooks, a free textbook project
- Wikiquote, a free encyclopedia of quotations
- Wikisource, a repository of source texts in any language which are either in the public domain or are released under the GFDL
- Wikinews, a news site, which is currently being tested
There are many other conceptually related projects, including Wikitravel.
In February 2002, most participants of the Spanish Wikipedia didn'Enciclopedia_Libre" title ="Enciclopedia Libre">Enciclopedia Libre.
Awards and nominations
In May 2004, Wikipedia won two major awards. The first was a Golden Nica for Digital Communities, awarded by Prix Ars Electronica; this came with a €10,000 grant and an invitation to present at the PAE Cyberarts Festival in Austria later that year. The second was a Judges' Webby award for "Community" . Wikipedia was also nominated for a "Best Practices" Webby.
In September 2004, the Japanese Wikipedia won an award from the country's major Advertisers' Association. This award, normally given to individuals for great contributions to the Web in Japanese, was accepted by a long-standing contributor on behalf of the project.
Mainstream media organisations mention Wikipedia from time to time.
- 4 December 2004 - Australian Broadcasting Corporation Radio National The Buzz "Cutting through the hype of our technological age" - presenter Richard Aedy conducted an interview with Wikipedia founder Jimmy Wales, that also canvassed the new Wikinews project. Aedy professed to be a fan of Wikipedia.
Google and Wikipedia
Google searching exclusively on Wikipedia content is possible using the following URL:
Yahoo! and Wikipedia
Yahoo! searching exclusively on Wikipedia content is possible using the following URL:
- Meta-Wikipedia - Policy-related and technical discussions about Wikipedia and its sister projects; includes a guide on establishing your own MediaWiki site.
- MediaWiki Phase III Software at SourceForge
- OpenFacts: Copies of Wikipedia content
- The Wikipedia Cafeshop
- Archive of Wikipedia press releases
- Wikipedia Trophy Box
- Size comparisons
- Wikipedia statistics
- The Free Universal Encyclopedia and Learning Resource by Richard Stallman (RMS)
- IBM History Flow: Technical experiment on "visualizing dynamic, evolving documents and the interactions of multiple collaborating authors". Uses various Wikipedia articles as example data.
- Operation of a Large Scale, General Purpose Wiki Website, November 2002, by Lars Aronsson, founder of susning.nu.
- Coase's Penguin by Yochai Benkler.
- Wikipedia in academic studies
- Andrea Ciffolilli. 'Phantom authority, self-selective recruitment and retention of members in virtual communities: The case of Wikipedia', First Monday, December 2003.
- Andrew Lih. 'Wikipedia as Participatory Journalism: Reliable Sources? Metrics for evaluating collaborative media as a news resource' (PDF), 5th International Symposium on Online Journalism, April 2004.
Reviews, endorsements, criticisms and discussion of Wikipedia
- Wikipedia's press coverage
- 1999 FSF endorsement of Nupedia (later updated to include Wikipedia)
- July 2001 Britannica or Nupedia? The Future of Free Encyclopedias - Larry Sanger'Britannica" title ="Britannica">Britannica's decision to charge fees (July 2001).
- November 2001 RMS describes Wikipedia as "exciting news"
- January 2003 Guardian Online: "Common Knowledge"
- August 2003 CNN Article about Wikipedia
- September 2003 Science magazine's NetWatch section gives a favourable short review of "The People's Encyclopedia"
- June 2004 The Economist: Beyond capitalism? discusses open source and Wikipedia
- October 2004 Wiki wars An article on Red Herring about contentious articles on Wikipedia
- October 2004 Simon Waldman on Wikipedia's success
- October 2004 Satirical article in The Onion
- November 2004 "The Faith-Based Encyclopedia" Robert McHenry, a former Britannica editor, reviews Wikipedia at Tech Central Station
- Criticisms of Wikipedia
- Responses to common criticisms
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