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.
Wikipedia's content is created by its users. No single person owns the content, and no article is ever finished. As such, Wikipedia is subject to some unique hardships  that do not afflict traditional encyclopedias. It has self-healing systems in place to deal with these challenges, and even a page designed to explain these systems .
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 290,000 articles in English and over 400,000 in other languages (as of June 2004 ).
Table of contents
HistoryApart from downtimes caused by technical problems and upgrades, Wikipedia has been in operation since January 10, 2001. See History of Wikipedia for more details.
AntecedentsThe idea of collecting all of the world's knowledge under a single roof goes back to the ancient 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. See Encyclopedia for more details.
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's future vision of the microfilm based Memex in As We May Think (1945). An important milestone along this path is also Ted Nelson's Project Xanadu (1960).
With the development of the Internet, many people attempted to develop online encyclopedia projects. See Internet encyclopedia project. Free software exponent Richard Stallman articulated the usefulness of a "Free Universal Encyclopedia and Learning Resource" in 1999. He described Wikipedia's formation as "exciting news", and his Free Software Foundation encourages people "to visit and contribute to the site".
Essential characteristicsThere 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 banned users, and excluding protected pages). #It is open 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.
VandalismOne pertinent issue on Wikipedia is "vandalism": silly or offensive edits of the site's articles. For example, 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, co-founder of Wikipedia, 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. That's fast: "We were surprised at how often we found vandalism, and then surprised again at how fast it was fixed," says Martin Wattenberg, a researcher in the IBM TJ Watson Research Center, in Cambridge, Mass. 
PoliciesWikipedia's participants (Wikipedians) commonly follow, and enforce, a few basic policies.
- First, because there are 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 systemic bias of individual participants can color the neutrality of an article. However, the aim is not to write articles from a single objective point of view — this is a common misunderstanding of the policy — but rather, to fairly present all views on an issue, attributed to their adherents in a neutral way. Of course, establishing a consensus on what views should be thus attributed can often require much (sometimes heated) discussion and debate.
- Second, there are a number of article naming conventions; for example, when several names exist, the most common one in the respective Wikipedia language is preferred.
- Third, 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's WikiWiki.
- Fourth, 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's sister projects, such as Wiktionary and Wikisource, are designed to be repositories for many alternative forms of reference material that do not fit well into Wikipedia.)
- Fifth, 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.
PersonnelWikipedia has been edited by thousands of people (referred to as Wikipedians). There is no editor-in-chief, as such. The two people who founded Wikipedia are Jimmy Wales (former CEO of the small Internet company Bomis, Inc.) and Larry Sanger. The wikipedia.com domain is registered under Wales' name. For the first thirteen months, Sanger was paid by Bomis to work on the project. Sanger was said to have taken a role of mediator at times, making decisions on issues that aroused contention. This was based not on formal authority, but on demands from users at large. Funding ran out for his position, leading to his resignation in February of 2002. Other current and past Bomis employees who have done some work on the encyclopedia include Tim Shell, one of the co-founders of Bomis, and its current CEO, and programmers Jason Richey and Toan Vo.
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 with 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 Redhat Linux. 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).
Sister projectsWikipedia has the following sister projects:
- 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
Downloading the databaseAnyone who wishes to use Wikipedia's open content for something that cannot best be done on Wikipedia 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. 
Awards and nominations
- Prix Ars Electronica, winner - in the category of Digital Communities; The World Starts With Me also won.
- The Webby Awards, winner of the "Community" section; was also nominated in the "Best Practices" section. See the winner's list
- MediaWiki Phase III Software at SourceForge
- OpenFacts: Copies of Wikipedia content
- The Wikipedia Cafeshop
- archive of Wikipedia press releases
Related papers and academic articles
- 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, Nov 2002, by Lars Aronsson, founder of susning.nu.
- "Wikipedia as Participatory Journalism: Reliable Sources? Metrics for evaluating collaborative media as a news resource", Apr 2004, by Andrew Lih.
Reviews, endorsements, and discussion of Wikipedia
- Official Wikipedia press coverage
- News articles that mention Wikipedia (updated regularly): Yahoo Google
- August 2003 CNN Article about Wikipedia
- November 2001 RMS describes Wikipedia as "exciting news"
- July 2001 Britannica or Nupedia? The Future of Free Encyclopedias - Larry Sanger's response to Britannica's decision to charge fee (July 2001).
- 1999 FSF endorsement of Wikipedia