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Sunday, November 26, 2023

Wikipedia

From Wikipedia, the free encyclopedia
Screenshot
Type of site
Online encyclopedia
Available in339 languages
Country of originUnited States
Owner
Created by
URLwikipedia.org
CommercialNo
RegistrationOptional
Users>294,736 active editors
>110,991,194 registered users
LaunchedJanuary 15, 2001
(22 years ago)
Current statusActive
Content license
CC Attribution / Share-Alike 4.0
Most text is also dual-licensed under GFDL; media licensing varies
Written inLAMP platform
OCLC number52075003

Wikipedia is a free-content online encyclopedia written and maintained by a community of volunteers, collectively known as Wikipedians, through open collaboration and using a wiki-based editing system called MediaWiki. Wikipedia is the largest and most-read reference work in history. It has consistently been one of the 10 most popular websites in the world, and, as of 2023, ranks as the 4th most viewed website by Semrush. Founded by Jimmy Wales and Larry Sanger on January 15, 2001, it is hosted by the Wikimedia Foundation, an American nonprofit organization.

Initially only available in English, editions in other languages were quickly developed. Wikipedia's editions when combined, comprise more than 62 million articles, attracting around 2 billion unique device visits per month and more than 14 million edits per month (about 5.2 edits per second on average) as of November 2023. As of November 2023, 25.56% of Wikipedia's traffic comes from the United States followed by Japan at 5.87%, United Kingdom at 5.44%, Germany at 5%, Russia at 4.78% and the remaining 53.36% split among other countries according to data provided by Similarweb.

Wikipedia has been praised for its enablement of the democratization of knowledge, extent of coverage, unique structure, and culture. It has been criticized for exhibiting systemic bias, particularly gender bias against women and geographical bias against the Global South (Eurocentrism). While the reliability of Wikipedia was frequently criticized in the 2000s, it has improved over time, receiving greater praise in the late 2010s and early 2020s, having become an important fact-checking site.

It has been censored by some national governments, ranging from specific pages to the entire site. Articles on breaking news are often accessed as sources for frequently updated information about those events.

History

Nupedia

Wikipedia founders Jimmy Wales (top) and Larry Sanger (bottom)

Various collaborative online encyclopedias were attempted before the start of Wikipedia, but with limited success. Wikipedia began as a complementary project for Nupedia, a free online English-language encyclopedia project whose articles were written by experts and reviewed under a formal process. It was founded on March 9, 2000, under the ownership of Bomis, a web portal company. Its main figures were Bomis CEO Jimmy Wales and Larry Sanger, editor-in-chief for Nupedia and later Wikipedia. Nupedia was initially licensed under its own Nupedia Open Content License, but before Wikipedia was founded, Nupedia switched to the GNU Free Documentation License at the urging of Richard Stallman. Wales is credited with defining the goal of making a publicly editable encyclopedia, while Sanger is credited with the strategy of using a wiki to reach that goal. On January 10, 2001, Sanger proposed on the Nupedia mailing list to create a wiki as a "feeder" project for Nupedia.

Launch and growth

The domains wikipedia.com (later redirecting to wikipedia.org) and wikipedia.org were registered on January 12, 2001, and January 13, 2001, respectively. Wikipedia was launched on January 15, 2001 as a single English-language edition at www.wikipedia.com, and was announced by Sanger on the Nupedia mailing list. The name originated from a blend of the words wiki and encyclopedia. Its integral policy of "neutral point-of-view" was codified in its first few months. Otherwise, there were initially relatively few rules, and it operated independently of Nupedia. Bomis originally intended it as a business for profit.

The Wikipedia home page on December 20, 2001

Wikipedia gained early contributors from Nupedia, Slashdot postings, and web search engine indexing. Language editions were created beginning in March 2001, with a total of 161 in use by the end of 2004. Nupedia and Wikipedia coexisted until the former's servers were taken down permanently in 2003, and its text was incorporated into Wikipedia. The English Wikipedia passed the mark of two million articles on September 9, 2007, making it the largest encyclopedia ever assembled, surpassing the Yongle Encyclopedia made during the Ming dynasty in 1408, which had held the record for almost 600 years.

Citing fears of commercial advertising and lack of control, users of the Spanish Wikipedia forked from Wikipedia to create Enciclopedia Libre in February 2002. Wales then announced that Wikipedia would not display advertisements, and changed Wikipedia's domain from wikipedia.com to wikipedia.org.

Though the English Wikipedia reached three million articles in August 2009, the growth of the edition, in terms of the numbers of new articles and of editors, appears to have peaked around early 2007. Around 1,800 articles were added daily to the encyclopedia in 2006; by 2013 that average was roughly 800. A team at the Palo Alto Research Center attributed this slowing of growth to the project's increasing exclusivity and resistance to change. Others suggest that the growth is flattening naturally because articles that could be called "low-hanging fruit"—topics that clearly merit an article—have already been created and built up extensively.

In November 2009, a researcher at the Rey Juan Carlos University in Madrid, Spain found that the English Wikipedia had lost 49,000 editors during the first three months of 2009; in comparison, it lost only 4,900 editors during the same period in 2008. The Wall Street Journal cited the array of rules applied to editing and disputes related to such content among the reasons for this trend. Wales disputed these claims in 2009, denying the decline and questioning the study's methodology. Two years later, in 2011, he acknowledged a slight decline, noting a decrease from "a little more than 36,000 writers" in June 2010 to 35,800 in June 2011. In the same interview, he also claimed the number of editors was "stable and sustainable". A 2013 MIT Technology Review article, "The Decline of Wikipedia", questioned this claim, revealing that since 2007, Wikipedia had lost a third of its volunteer editors, and that those remaining had focused increasingly on minutiae. In July 2012, The Atlantic reported that the number of administrators was also in decline. In the November 25, 2013, issue of New York magazine, Katherine Ward stated, "Wikipedia, the sixth-most-used website, is facing an internal crisis."

The number of active English Wikipedia editors has since remained steady after a long period of decline.

Milestones

Cartogram showing number of articles in each European language as of January 2019. One square represents 10,000 articles. Languages with fewer than 10,000 articles are represented by one square. Languages are grouped by language family and each language family is presented by a separate color.

In January 2007, Wikipedia first became one of the ten most popular websites in the United States, according to Comscore Networks. With 42.9 million unique visitors, it was ranked #9, surpassing The New York Times (#10) and Apple (#11). This marked a significant increase over January 2006, when Wikipedia ranked 33rd, with around 18.3 million unique visitors. In 2014, it received eight billion page views every month. On February 9, 2014, The New York Times reported that Wikipedia had 18 billion page views and nearly 500 million unique visitors a month, "according to the ratings firm comScore". As of March 2023, it ranked 6th in popularity, according to Similarweb. Loveland and Reagle argue that, in process, Wikipedia follows a long tradition of historical encyclopedias that have accumulated improvements piecemeal through "stigmergic accumulation".

On January 18, 2012, the English Wikipedia participated in a series of coordinated protests against two proposed laws in the United States Congress—the Stop Online Piracy Act (SOPA) and the PROTECT IP Act (PIPA)—by blacking out its pages for 24 hours. More than 162 million people viewed the blackout explanation page that temporarily replaced its content.

In January 2013, 274301 Wikipedia, an asteroid, was named after Wikipedia; in October 2014, Wikipedia was honored with the Wikipedia Monument; and, in July 2015, 106 of the 7,473 700-page volumes of Wikipedia became available as Print Wikipedia. In April 2019, an Israeli lunar lander, Beresheet, crash landed on the surface of the Moon carrying a copy of nearly all of the English Wikipedia engraved on thin nickel plates; experts say the plates likely survived the crash. In June 2019, scientists reported that all 16 GB of article text from the English Wikipedia had been encoded into synthetic DNA.

On January 20, 2014, Subodh Varma reporting for The Economic Times indicated that not only had Wikipedia's growth stalled, it "had lost nearly ten percent of its page views last year. There was a decline of about two billion between December 2012 and December 2013. Its most popular versions are leading the slide: page-views of the English Wikipedia declined by twelve percent, those of German version slid by 17 percent and the Japanese version lost nine percent." Varma added, "While Wikipedia's managers think that this could be due to errors in counting, other experts feel that Google's Knowledge Graphs project launched last year may be gobbling up Wikipedia users." When contacted on this matter, Clay Shirky, associate professor at New York University and fellow at Harvard's Berkman Klein Center for Internet & Society said that he suspected much of the page-view decline was due to Knowledge Graphs, stating, "If you can get your question answered from the search page, you don't need to click [any further]." By the end of December 2016, Wikipedia was ranked the fifth most popular website globally.

As of January 2023, 55,791 English Wikipedia articles have been cited 92,300 times in scholarly journals, from which cloud computing was the most cited page.

On January 18, 2023, Wikipedia debuted a new website redesign, called "Vector 2022". It featured a redesigned menu bar, moving the table of contents to the left as a sidebar, and numerous changes in the locations of buttons like the language selection tool. The update initially received backlash, most notably when editors of the Swahili Wikipedia unanimously voted to revert the changes.

Openness

Differences between versions of an article are highlighted

Unlike traditional encyclopedias, Wikipedia follows the procrastination principle regarding the security of its content, meaning that it waits until a problem arises to fix it.

Restrictions

Due to Wikipedia's increasing popularity, some editions, including the English version, have introduced editing restrictions for certain cases. For instance, on the English Wikipedia and some other language editions, only registered users may create a new article. On the English Wikipedia, among others, particularly controversial, sensitive, or vandalism-prone pages have been protected to varying degrees. A frequently vandalized article can be "semi-protected" or "extended confirmed protected", meaning that only "autoconfirmed" or "extended confirmed" editors can modify it. A particularly contentious article may be locked so that only administrators can make changes. A 2021 article in the Columbia Journalism Review identified Wikipedia's page-protection policies as "perhaps the most important" means at its disposal to "regulate its market of ideas".

In certain cases, all editors are allowed to submit modifications, but review is required for some editors, depending on certain conditions. For example, the German Wikipedia maintains "stable versions" of articles which have passed certain reviews. Following protracted trials and community discussion, the English Wikipedia introduced the "pending changes" system in December 2012. Under this system, new and unregistered users' edits to certain controversial or vandalism-prone articles are reviewed by established users before they are published.

Review of changes

Wikipedia's editing interface

Although changes are not systematically reviewed, Wikipedia's software provides tools allowing anyone to review changes made by others. Each article's History page links to each revision. On most articles, anyone can view the latest changes and undo others' revisions by clicking a link on the article's History page. Registered users may maintain a "watchlist" of articles that interest them so they can be notified of changes. "New pages patrol" is a process where newly created articles are checked for obvious problems.

In 2003, economics PhD student Andrea Ciffolilli argued that the low transaction costs of participating in a wiki created a catalyst for collaborative development, and that features such as allowing easy access to past versions of a page favored "creative construction" over "creative destruction".

Vandalism

Any change that deliberately compromises Wikipedia's integrity is considered vandalism. The most common and obvious types of vandalism include additions of obscenities and crude humor; it can also include advertising and other types of spam. Sometimes editors commit vandalism by removing content or entirely blanking a given page. Less common types of vandalism, such as the deliberate addition of plausible but false information, can be more difficult to detect. Vandals can introduce irrelevant formatting, modify page semantics such as the page's title or categorization, manipulate the article's underlying code, or use images disruptively.

White-haired elderly gentleman in suit and tie speaks at a podium.
American journalist John Seigenthaler (1927–2014), subject of the Seigenthaler incident

Obvious vandalism is generally easy to remove from Wikipedia articles; the median time to detect and fix it is a few minutes. However, some vandalism takes much longer to detect and repair.

In the Seigenthaler biography incident, an anonymous editor introduced false information into the biography of American political figure John Seigenthaler in May 2005, falsely presenting him as a suspect in the assassination of John F. Kennedy. It remained uncorrected for four months. Seigenthaler, the founding editorial director of USA Today and founder of the Freedom Forum First Amendment Center at Vanderbilt University, called Wikipedia co-founder Jimmy Wales and asked whether he had any way of knowing who contributed the misinformation. Wales said he did not, although the perpetrator was eventually traced. After the incident, Seigenthaler described Wikipedia as "a flawed and irresponsible research tool". The incident led to policy changes at Wikipedia for tightening up the verifiability of biographical articles of living people.

Edit warring

Wikipedians often have disputes regarding content, which may result in repeated competing changes to an article, known as "edit warring". It is widely seen as a resource-consuming scenario where no useful knowledge is added, and criticized as creating a competitive and conflict-based editing culture associated with traditional masculine gender roles.

Taha Yasseri of the University of Oxford examined editing conflicts and their resolution in a 2013 study. Yasseri contended that simple reverts or "undo" operations were not the most significant measure of counterproductive work behavior at Wikipedia. He relied instead on "mutually reverting edit pairs", where one editor reverts the edit of another editor who then, in sequence, returns to revert the first editor. The results were tabulated for several language versions of Wikipedia. The English Wikipedia's three largest conflict rates belonged to the articles George W. Bush, anarchism, and Muhammad. By comparison, for the German Wikipedia, the three largest conflict rates at the time of the study were for the articles covering Croatia, Scientology, and 9/11 conspiracy theories.

Policies and content

External videos
video icon Jimmy Wales, The Birth of Wikipedia, 2006, TED talks, 20 minutes
video icon Katherine Maher, What Wikipedia Teaches Us About Balancing Truth and Beliefs, 2022, TED talks, 15 minutes

Content in Wikipedia is subject to the laws (in particular, copyright laws) of the United States and of the US state of Virginia, where the majority of Wikipedia's servers are located. By using the site, one agrees to the Wikimedia Foundation Terms of Use and Privacy Policy; some of the main rules are that contributors are legally responsible for their edits and contributions, that they should follow the policies that govern each of the independent project editions, and they may not engage in activities, whether legal or illegal, that may be harmful to other users. In addition to the terms, the Foundation has developed policies, described as the "official policies of the Wikimedia Foundation".

The fundamental principles of the Wikipedia community are embodied in the "Five pillars", while the detailed editorial principles are expressed in numerous policies and guidelines intended to appropriately shape content. The five pillars are:

  • Wikipedia is an encyclopedia
  • Wikipedia is written from a neutral point of view
  • Wikipedia is free content that anyone can use, edit, and distribute
  • Wikipedia's editors should treat each other with respect and civility
  • Wikipedia has no firm rules

The rules developed by the community are stored in wiki form, and Wikipedia editors write and revise the website's policies and guidelines in accordance with community consensus. Editors can enforce the rules by deleting or modifying non-compliant material. Originally, rules on the non-English editions of Wikipedia were based on a translation of the rules for the English Wikipedia. They have since diverged to some extent.

The two most commonly used namespaces across all editions of Wikipedia are: The article namespace (which are the articles of the encyclopedia) and the category namespace (which are a collection of pages such as articles). In addition, there have been various books and reading list that are composed completely of articles and categories of a certain Wikipedia.

Content policies and guidelines

According to the rules on the English Wikipedia community, each entry in Wikipedia must be about a topic that is encyclopedic and is not a dictionary entry or dictionary-style. A topic should also meet Wikipedia's standards of "notability", which generally means that the topic must have been covered in mainstream media or major academic journal sources that are independent of the article's subject. Further, Wikipedia intends to convey only knowledge that is already established and recognized. It must not present original research. A claim that is likely to be challenged requires a reference to a reliable source, as do all quotations. Among Wikipedia editors, this is often phrased as "verifiability, not truth" to express the idea that the readers, not the encyclopedia, are ultimately responsible for checking the truthfulness of the articles and making their own interpretations. This can at times lead to the removal of information that, though valid, is not properly sourced. Finally, Wikipedia must not take sides.

Governance

Wikipedia's initial anarchy integrated democratic and hierarchical elements over time. An article is not considered to be owned by its creator or any other editor, nor by the subject of the article.

Administrators

Editors in good standing in the community can request extra user rights, granting them the technical ability to perform certain special actions. In particular, editors can choose to run for "adminship", which includes the ability to delete pages or prevent them from being changed in cases of severe vandalism or editorial disputes. Administrators are not supposed to enjoy any special privilege in decision-making; instead, their powers are mostly limited to making edits that have project-wide effects and thus are disallowed to ordinary editors, and to implement restrictions intended to prevent disruptive editors from making unproductive edits.

By 2012, fewer editors were becoming administrators compared to Wikipedia's earlier years, in part because the process of vetting potential administrators had become more rigorous. In 2022, there was a particularly contentious request for adminship over the candidate's anti-Trump views; ultimately, they were granted adminship.

Dispute resolution

Over time, Wikipedia has developed a semiformal dispute resolution process. To determine community consensus, editors can raise issues at appropriate community forums, seek outside input through third opinion requests, or initiate a more general community discussion known as a "request for comment".

Wikipedia encourages local resolutions of conflicts, which Jemielniak argues is quite unique in organization studies, though there has been some recent interest in consensus building in the field. Joseph Reagle and Sue Gardner argue that the approaches to consensus building are similar to those used by Quakers. A difference from Quaker meetings is the absence of a facilitator in the presence of disagreement, a role played by the clerk in Quaker meetings.

Arbitration Committee

The Arbitration Committee presides over the ultimate dispute resolution process. Although disputes usually arise from a disagreement between two opposing views on how an article should read, the Arbitration Committee explicitly refuses to directly rule on the specific view that should be adopted. Statistical analyses suggest that the committee ignores the content of disputes and rather focuses on the way disputes are conducted, functioning not so much to resolve disputes and make peace between conflicting editors, but to weed out problematic editors while allowing potentially productive editors back in to participate. Therefore, the committee does not dictate the content of articles, although it sometimes condemns content changes when it deems the new content violates Wikipedia policies (for example, if the new content is considered biased). Commonly used solutions include cautions and probations (used in 63% of cases) and banning editors from articles (43%), subject matters (23%), or Wikipedia (16%). Complete bans from Wikipedia are generally limited to instances of impersonation and anti-social behavior. When conduct is not impersonation or anti-social, but rather edit warring and other violations of editing policies, solutions tend to be limited to warnings.

Community

Each article and each user of Wikipedia has an associated and dedicated "talk" page. These form the primary communication channel for editors to discuss, coordinate and debate.

Wikipedia's community has been described as cultlike, although not always with entirely negative connotations. Its preference for cohesiveness, even if it requires compromise that includes disregard of credentials, has been referred to as "anti-elitism".

Wikipedia does not require that its editors and contributors provide identification. As Wikipedia grew, "Who writes Wikipedia?" became one of the questions frequently asked there. Jimmy Wales once argued that only "a community ... a dedicated group of a few hundred volunteers" makes the bulk of contributions to Wikipedia and that the project is therefore "much like any traditional organization". In 2008, a Slate magazine article reported that: "According to researchers in Palo Alto, one percent of Wikipedia users are responsible for about half of the site's edits." This method of evaluating contributions was later disputed by Aaron Swartz, who noted that several articles he sampled had large portions of their content (measured by number of characters) contributed by users with low edit counts.

The English Wikipedia has 6,750,937 articles, 46,542,024 registered editors, and 121,987 active editors. An editor is considered active if they have made one or more edits in the past 30 days.

Editors who fail to comply with Wikipedia cultural rituals, such as signing talk page comments, may implicitly signal that they are Wikipedia outsiders, increasing the odds that Wikipedia insiders may target or discount their contributions. Becoming a Wikipedia insider involves non-trivial costs: the contributor is expected to learn Wikipedia-specific technological codes, submit to a sometimes convoluted dispute resolution process, and learn a "baffling culture rich with in-jokes and insider references". Editors who do not log in are in some sense "second-class citizens" on Wikipedia, as "participants are accredited by members of the wiki community, who have a vested interest in preserving the quality of the work product, on the basis of their ongoing participation", but the contribution histories of anonymous unregistered editors recognized only by their IP addresses cannot be attributed to a particular editor with certainty.

Studies

A 2007 study by researchers from Dartmouth College found that "anonymous and infrequent contributors to Wikipedia ... are as reliable a source of knowledge as those contributors who register with the site". Jimmy Wales stated in 2009 that "[I]t turns out over 50% of all the edits are done by just 0.7% of the users ... 524 people ... And in fact, the most active 2%, which is 1400 people, have done 73.4% of all the edits." However, Business Insider editor and journalist Henry Blodget showed in 2009 that in a random sample of articles, most Wikipedia content (measured by the amount of contributed text that survives to the latest sampled edit) is created by "outsiders", while most editing and formatting is done by "insiders".

A 2008 study found that Wikipedians were less agreeable, open, and conscientious than others, although a later commentary pointed out serious flaws, including that the data showed higher openness and that the differences with the control group and the samples were small. According to a 2009 study, there is "evidence of growing resistance from the Wikipedia community to new content".

Diversity

Several studies have shown that most Wikipedia contributors are male. Notably, the results of a Wikimedia Foundation survey in 2008 showed that only 13 percent of Wikipedia editors were female. Because of this, universities throughout the United States tried to encourage women to become Wikipedia contributors. Similarly, many of these universities, including Yale and Brown, gave college credit to students who create or edit an article relating to women in science or technology. Andrew Lih, a professor and scientist, said that the reason he thought the number of male contributors outnumbered the number of females so greatly was because identifying as a woman may expose oneself to "ugly, intimidating behavior". Data has shown that Africans are underrepresented among Wikipedia editors.

Language editions

Distribution of the 62,092,840 articles in different language editions (as of November 26, 2023)

  English (10.9%)
  Cebuano (9.9%)
  German (4.6%)
  Swedish (4.1%)
  French (4.1%)
  Dutch (3.4%)
  Russian (3.1%)
  Spanish (3.1%)
  Italian (3%)
  Egyptian Arabic (2.6%)
  Polish (2.6%)
  Japanese (2.2%)
  Chinese (2.2%)
  Ukrainian (2.1%)
  Vietnamese (2.1%)
  Waray (2%)
  Arabic (2%)
  Other (36%)
Most viewed editions of Wikipedia over time
Most edited editions of Wikipedia over time

There are currently 339 language editions of Wikipedia (also called language versions, or simply Wikipedias). As of November 2023, the six largest, in order of article count, are the English, Cebuano, German, Swedish, French, and Dutch Wikipedias. The second and fourth-largest Wikipedias owe their position to the article-creating bot Lsjbot, which as of 2013 had created about half the articles on the Swedish Wikipedia, and most of the articles in the Cebuano and Waray Wikipedias. The latter are both languages of the Philippines.

In addition to the top six, twelve other Wikipedias have more than a million articles each (Russian, Spanish, Italian, Egyptian Arabic, Polish, Japanese, Chinese, Ukrainian, Vietnamese, Waray, Arabic and Portuguese), seven more have over 500,000 articles (Persian, Catalan, Serbian, Indonesian, Korean, Norwegian and Chechen), 44 more have over 100,000, and 82 more have over 10,000. The largest, the English Wikipedia, has over 6.7 million articles. As of January 2021, the English Wikipedia receives 48% of Wikipedia's cumulative traffic, with the remaining split among the other languages. The top 10 editions represent approximately 85% of the total traffic.

Logarithmic graph of the 20 largest language editions of Wikipedia
(as of 26 November 2023)
(millions of articles)
0.1 0.3 1 3









English 6,750,937
Cebuano 6,122,111
German 2,856,509
Swedish 2,575,919
French 2,571,628
Dutch 2,139,995
Russian 1,949,265
Spanish 1,909,256
Italian 1,837,017
Egyptian Arabic 1,620,739
Polish 1,591,264
Japanese 1,394,429
Chinese 1,389,196
Ukrainian 1,298,645
Vietnamese 1,289,190
Waray 1,266,331
Arabic 1,222,616
Portuguese 1,113,918
Persian 982,359
Catalan 739,189

The unit for the numbers in bars is articles.

Since Wikipedia is based on the Web and therefore worldwide, contributors to the same language edition may use different dialects or may come from different countries (as is the case for the English edition). These differences may lead to some conflicts over spelling differences (e.g. colour versus color) or points of view.

Though the various language editions are held to global policies such as "neutral point of view", they diverge on some points of policy and practice, most notably on whether images that are not licensed freely may be used under a claim of fair use.

Jimmy Wales has described Wikipedia as "an effort to create and distribute a free encyclopedia of the highest possible quality to every single person on the planet in their own language". Though each language edition functions more or less independently, some efforts are made to supervise them all. They are coordinated in part by Meta-Wiki, the Wikimedia Foundation's wiki devoted to maintaining all its projects (Wikipedia and others). For instance, Meta-Wiki provides important statistics on all language editions of Wikipedia, and it maintains a list of articles every Wikipedia should have. The list concerns basic content by subject: biography, history, geography, society, culture, science, technology, and mathematics. It is not rare for articles strongly related to a particular language not to have counterparts in another edition. For example, articles about small towns in the United States might be available only in English, even when they meet the notability criteria of other language Wikipedia projects.

Estimation of contributions shares from different regions in the world to different Wikipedia editions

Translated articles represent only a small portion of articles in most editions, in part because those editions do not allow fully automated translation of articles. Articles available in more than one language may offer "interwiki links", which link to the counterpart articles in other editions.

A study published by PLOS One in 2012 also estimated the share of contributions to different editions of Wikipedia from different regions of the world. It reported that the proportion of the edits made from North America was 51% for the English Wikipedia, and 25% for the simple English Wikipedia.

English Wikipedia editor numbers

On March 1, 2014, The Economist, in an article titled "The Future of Wikipedia", cited a trend analysis concerning data published by the Wikimedia Foundation stating that "the number of editors for the English-language version has fallen by a third in seven years." The attrition rate for active editors in English Wikipedia was cited by The Economist as substantially in contrast to statistics for Wikipedia in other languages (non-English Wikipedia). The Economist reported that the number of contributors with an average of five or more edits per month was relatively constant since 2008 for Wikipedia in other languages at approximately 42,000 editors within narrow seasonal variances of about 2,000 editors up or down. The number of active editors in English Wikipedia, by sharp comparison, was cited as peaking in 2007 at approximately 50,000 and dropping to 30,000 by the start of 2014.

In contrast, the trend analysis for Wikipedia in other languages (non-English Wikipedia) shows success in retaining active editors on a renewable and sustained basis, with their numbers remaining relatively constant at approximately 42,000. No comment was made concerning which of the differentiated edit policy standards from Wikipedia in other languages (non-English Wikipedia) would provide a possible alternative to English Wikipedia for effectively improving substantial editor attrition rates on the English-language Wikipedia.

Reception

Various Wikipedians have criticized Wikipedia's large and growing regulation, which includes more than fifty policies and nearly 150,000 words as of 2014.

Critics have stated that Wikipedia exhibits systemic bias. In 2010, columnist and journalist Edwin Black described Wikipedia as being a mixture of "truth, half-truth, and some falsehoods". Articles in The Chronicle of Higher Education and The Journal of Academic Librarianship have criticized Wikipedia's "Undue Weight" policy, concluding that Wikipedia explicitly is not designed to provide correct information about a subject, but rather focus on all the major viewpoints on the subject, give less attention to minor ones, and creates omissions that can lead to false beliefs based on incomplete information.

Journalists Oliver Kamm and Edwin Black alleged (in 2010 and 2011 respectively) that articles are dominated by the loudest and most persistent voices, usually by a group with an "ax to grind" on the topic. A 2008 article in Education Next Journal concluded that as a resource about controversial topics, Wikipedia is subject to manipulation and spin.

In 2020, Omer Benjakob and Stephen Harrison noted that "Media coverage of Wikipedia has radically shifted over the past two decades: once cast as an intellectual frivolity, it is now lauded as the 'last bastion of shared reality' online."

Multiple news networks and pundits have accused Wikipedia of being ideologically biased. In February 2021, Fox News accused Wikipedia of whitewashing communism and socialism and having too much "leftist bias". Wikipedia co-founder Sanger said that Wikipedia has become a "propaganda" for the left-leaning "establishment" and warned the site can no longer be trusted. In 2022, libertarian John Stossel opined that Wikipedia, a site he financially supported at one time, appeared to have gradually taken a significant turn in bias to the political left, specifically on political topics. Some studies highlight the fact that Wikipedia (and in particular the English Wikipedia) has a “western cultural bias” (or “pro-western bias”) or “Eurocentric bias”, reiterating, says Anna Samoilenko, “similar biases that are found in the ‘ivory tower’ of academic historiography”. Due to this persistent Eurocentrism, scholars like Carwil Bjork-James or the authors of ‘'The colonization of Wikipedia: evidence from characteristic editing behaviors of warring camps'’ call for a “decolonization” of Wikipedia.

Accuracy of content

External audio
audio icon The Great Book of Knowledge, Part 1, Ideas with Paul Kennedy, CBC, January 15, 2014

Articles for traditional encyclopedias such as Encyclopædia Britannica are written by experts, lending such encyclopedias a reputation for accuracy. However, a peer review in 2005 of forty-two scientific entries on both Wikipedia and Encyclopædia Britannica by the science journal Nature found few differences in accuracy, and concluded that "the average science entry in Wikipedia contained around four inaccuracies; Britannica, about three." Joseph Reagle suggested that while the study reflects "a topical strength of Wikipedia contributors" in science articles, "Wikipedia may not have fared so well using a random sampling of articles or on humanities subjects." Others raised similar critiques.he findings by Nature were disputed by Encyclopædia Britannica, and in response, Nature gave a rebuttal of the points raised by Britannica. In addition to the point-for-point disagreement between these two parties, others have examined the sample size and selection method used in the Nature effort, and suggested a "flawed study design" (in Nature's manual selection of articles, in part or in whole, for comparison), absence of statistical analysis (e.g., of reported confidence intervals), and a lack of study "statistical power" (i.e., owing to small sample size, 42 or 4 × 101 articles compared, vs >105 and >106 set sizes for Britannica and the English Wikipedia, respectively).

As a consequence of the open structure, Wikipedia "makes no guarantee of validity" of its content, since no one is ultimately responsible for any claims appearing in it. Concerns have been raised by PC World in 2009 regarding the lack of accountability that results from users' anonymity, the insertion of false information, vandalism, and similar problems.

Economist Tyler Cowen wrote: "If I had to guess whether Wikipedia or the median refereed journal article on economics was more likely to be true after a not so long think I would opt for Wikipedia." He comments that some traditional sources of non-fiction suffer from systemic biases, and novel results, in his opinion, are over-reported in journal articles as well as relevant information being omitted from news reports. However, he also cautions that errors are frequently found on Internet sites and that academics and experts must be vigilant in correcting them. Amy Bruckman has argued that, due to the number of reviewers, "the content of a popular Wikipedia page is actually the most reliable form of information ever created". In September 2022, The Sydney Morning Herald journalist Liam Mannix noted that, "There's no reason to expect Wikipedia to be accurate... And yet it [is]." Mannix further discussed the multiple studies that have proved Wikipedia to be generally as reliable as Encyclopedia Britannica, summarizing that, "...turning our back on such an extraordinary resource is... well, a little petty."

Critics argue that Wikipedia's open nature and a lack of proper sources for most of the information makes it unreliable. Some commentators suggest that Wikipedia may be reliable, but that the reliability of any given article is not clear. Editors of traditional reference works such as the Encyclopædia Britannica have questioned the project's utility and status as an encyclopedia. Wikipedia co-founder Jimmy Wales has claimed that Wikipedia has largely avoided the problem of "fake news" because the Wikipedia community regularly debates the quality of sources in articles.

External videos
video icon Inside Wikipedia – Attack of the PR Industry, Deutsche Welle, 7:13 mins

Wikipedia's open structure inherently makes it an easy target for Internet trolls, spammers, and various forms of paid advocacy seen as counterproductive to the maintenance of a neutral and verifiable online encyclopedia. In response to paid advocacy editing and undisclosed editing issues, Wikipedia was reported in an article in The Wall Street Journal to have strengthened its rules and laws against undisclosed editing. The article stated that: "Beginning Monday [from the date of the article, June 16, 2014], changes in Wikipedia's terms of use will require anyone paid to edit articles to disclose that arrangement. Katherine Maher, the nonprofit Wikimedia Foundation's chief communications officer, said the changes address a sentiment among volunteer editors that, 'we're not an advertising service; we're an encyclopedia.'" These issues, among others, had been parodied since the first decade of Wikipedia, notably by Stephen Colbert on The Colbert Report.

Legal Research in a Nutshell (2011), cites Wikipedia as a "general source" that "can be a real boon" in "coming up to speed in the law governing a situation" and, "while not authoritative, can provide basic facts as well as leads to more in-depth resources".

Discouragement in education

Some university lecturers discourage students from citing any encyclopedia in academic work, preferring primary sources; some specifically prohibit Wikipedia citations. Wales stresses that encyclopedias of any type are not usually appropriate to use as citable sources, and should not be relied upon as authoritative. Wales once (2006 or earlier) said he receives about ten emails weekly from students saying they got failing grades on papers because they cited Wikipedia; he told the students they got what they deserved. "For God's sake, you're in college; don't cite the encyclopedia", he said.

In February 2007, an article in The Harvard Crimson newspaper reported that a few of the professors at Harvard University were including Wikipedia articles in their syllabi, although without realizing the articles might change. In June 2007, Michael Gorman, former president of the American Library Association, condemned Wikipedia, along with Google, stating that academics who endorse the use of Wikipedia are "the intellectual equivalent of a dietitian who recommends a steady diet of Big Macs with everything".

A 2020 research study published in Studies in Higher Education argued that Wikipedia could be applied in the higher education "flipped classroom", an educational model where students learn before coming to class and apply it in classroom activities. The experimental group was instructed to learn before class and get immediate feedback before going in (the flipped classroom model), while the control group was given direct instructions in class (the conventional classroom model). The groups were then instructed to collaboratively develop Wikipedia entries, which would be graded in quality after the study. The results showed that the experimental group yielded more Wikipedia entries and received higher grades in quality. The study concluded that learning with Wikipedia in flipped classrooms was more effective than in conventional classrooms, demonstrating Wikipedia could be used as an educational tool in higher education.

Medical information

On March 5, 2014, Julie Beck writing for The Atlantic magazine in an article titled "Doctors' #1 Source for Healthcare Information: Wikipedia", stated that "Fifty percent of physicians look up conditions on the (Wikipedia) site, and some are editing articles themselves to improve the quality of available information." Beck continued to detail in this article new programs of Amin Azzam at the University of San Francisco to offer medical school courses to medical students for learning to edit and improve Wikipedia articles on health-related issues, as well as internal quality control programs within Wikipedia organized by James Heilman to improve a group of 200 health-related articles of central medical importance up to Wikipedia's highest standard of articles using its Featured Article and Good Article peer-review evaluation process. In a May 7, 2014, follow-up article in The Atlantic titled "Can Wikipedia Ever Be a Definitive Medical Text?", Julie Beck quotes WikiProject Medicine's James Heilman as stating: "Just because a reference is peer-reviewed doesn't mean it's a high-quality reference." Beck added that: "Wikipedia has its own peer review process before articles can be classified as 'good' or 'featured'. Heilman, who has participated in that process before, says 'less than one percent' of Wikipedia's medical articles have passed."

Coverage of topics and systemic bias

Wikipedia seeks to create a summary of all human knowledge in the form of an online encyclopedia, with each topic covered encyclopedically in one article. Since it has terabytes of disk space, it can have far more topics than can be covered by any printed encyclopedia. The exact degree and manner of coverage on Wikipedia is under constant review by its editors, and disagreements are not uncommon (see deletionism and inclusionism). Wikipedia contains materials that some people may find objectionable, offensive, or pornographic. The "Wikipedia is not censored" policy has sometimes proved controversial: in 2008, Wikipedia rejected an online petition against the inclusion of images of Muhammad in the English edition of its Muhammad article, citing this policy. The presence of politically, religiously, and pornographically sensitive materials in Wikipedia has led to the censorship of Wikipedia by national authorities in China and Pakistan, amongst other countries.

Pie chart of Wikipedia content by subject as of January 2008

A 2008 study conducted by researchers at Carnegie Mellon University and Palo Alto Research Center gave a distribution of topics as well as growth (from July 2006 to January 2008) in each field:

  • Culture and Arts: 30% (210%)
  • Biographies and persons: 15% (97%)
  • Geography and places: 14% (52%)
  • Society and social sciences: 12% (83%)
  • History and events: 11% (143%)
  • Natural and Physical Sciences: 9% (213%)
  • Technology and Applied Science: 4% (−6%)
  • Religions and belief systems: 2% (38%)
  • Health: 2% (42%)
  • Mathematics and logic: 1% (146%)
  • Thought and Philosophy: 1% (160%)

These numbers refer only to the number of articles: it is possible for one topic to contain a large number of short articles and another to contain a small number of large ones. Through its "Wikipedia Loves Libraries" program, Wikipedia has partnered with major public libraries such as the New York Public Library for the Performing Arts to expand its coverage of underrepresented subjects and articles.

A 2011 study conducted by researchers at the University of Minnesota indicated that male and female editors focus on different coverage topics. There was a greater concentration of females in the "people and arts" category, while males focus more on "geography and science".

Coverage of topics and bias

Research conducted by Mark Graham of the Oxford Internet Institute in 2009 indicated that the geographic distribution of article topics is highly uneven, Africa being the most underrepresented.[239] Across 30 language editions of Wikipedia, historical articles and sections are generally Eurocentric and focused on recent events.

An editorial in The Guardian in 2014 claimed that more effort went into providing references for a list of female porn actors than a list of women writers. Data has also shown that Africa-related material often faces omission; a knowledge gap that a July 2018 Wikimedia conference in Cape Town sought to address.

Systemic biases

Academic studies of Wikipedia have consistently shown that Wikipedia systematically over-represents a point of view (POV) belonging to a particular demographic described as the "average Wikipedian", who is an educated, technically inclined, English speaking white male, aged 15–49 from a developed Christian country in the northern hemisphere. This POV is over-represented in relation to all existing POVs. This systemic bias in editor demographic results in cultural bias, gender bias, and geographical bias on Wikipedia. There are two broad types of bias, which are implicit (when a topic is omitted) and explicit (when a certain POV is over-represented in an article or by references).

Interdisciplinary scholarly assessments of Wikipedia articles have found that while articles are typically accurate and free of misinformation, they are also typically incomplete and fail to present all perspectives with a neutral point of view. In 2011, Wales claimed that the unevenness of coverage is a reflection of the demography of the editors, citing for example "biographies of famous women through history and issues surrounding early childcare". The October 22, 2013, essay by Tom Simonite in MIT's Technology Review titled "The Decline of Wikipedia" discussed the effect of systemic bias and policy creep on the downward trend in the number of editors.

Explicit content

Wikipedia has been criticized for allowing information about graphic content. Articles depicting what some critics have called objectionable content (such as feces, cadaver, human penis, vulva, and nudity) contain graphic pictures and detailed information easily available to anyone with access to the internet, including children.

The site also includes sexual content such as images and videos of masturbation and ejaculation, illustrations of zoophilia, and photos from hardcore pornographic films in its articles. It also has non-sexual photographs of nude children.

The Wikipedia article about Virgin Killer—a 1976 album from the German rock band Scorpions—features a picture of the album's original cover, which depicts a naked prepubescent girl. The original release cover caused controversy and was replaced in some countries. In December 2008, access to the Wikipedia article Virgin Killer was blocked for four days by most Internet service providers in the United Kingdom after the Internet Watch Foundation (IWF) decided the album cover was a potentially illegal indecent image and added the article's URL to a "blacklist" it supplies to British internet service providers.

In April 2010, Sanger wrote a letter to the Federal Bureau of Investigation, outlining his concerns that two categories of images on Wikimedia Commons contained child pornography, and were in violation of US federal obscenity law. Sanger later clarified that the images, which were related to pedophilia and one about lolicon, were not of real children, but said that they constituted "obscene visual representations of the sexual abuse of children", under the PROTECT Act of 2003. That law bans photographic child pornography and cartoon images and drawings of children that are obscene under American law. Sanger also expressed concerns about access to the images on Wikipedia in schools. Wikimedia Foundation spokesman Jay Walsh strongly rejected Sanger's accusation, saying that Wikipedia did not have "material we would deem to be illegal. If we did, we would remove it." Following the complaint by Sanger, Wales deleted sexual images without consulting the community. After some editors who volunteered to maintain the site argued that the decision to delete had been made hastily, Wales voluntarily gave up some of the powers he had held up to that time as part of his co-founder status. He wrote in a message to the Wikimedia Foundation mailing-list that this action was "in the interest of encouraging this discussion to be about real philosophical/content issues, rather than be about me and how quickly I acted". Critics, including Wikipediocracy, noticed that many of the pornographic images deleted from Wikipedia since 2010 have reappeared.

Privacy

One privacy concern in the case of Wikipedia is the right of a private citizen to remain a "private citizen" rather than a "public figure" in the eyes of the law. It is a battle between the right to be anonymous in cyberspace and the right to be anonymous in real life. The Wikimedia Foundation's privacy policy states, "we believe that you shouldn't have to provide personal information to participate in the free knowledge movement", and states that "personal information" may be shared "For legal reasons", "To Protect You, Ourselves & Others", or "To Understand & Experiment".

In January 2006, a German court ordered the German Wikipedia shut down within Germany because it stated the full name of Boris Floricic, aka "Tron", a deceased hacker. On February 9, 2006, the injunction against Wikimedia Deutschland was overturned, with the court rejecting the notion that Tron's right to privacy or that of his parents was being violated.

Wikipedia has a "Volunteer Response Team" that uses Znuny, a free and open-source software fork of OTRS to handle queries without having to reveal the identities of the involved parties. This is used, for example, in confirming the permission for using individual images and other media in the project.

In late April 2023, Wikimedia Foundation announced that Wikipedia will not submit to any age verifications that may be required by the Online Safety Bill. Rebecca MacKinnon of the Wikimedia Foundation said that such checks would run counter to the website's commitment to minimal data collection on its contributors and readers.

Sexism

Wikipedia was described in 2015 as harboring a battleground culture of sexism and harassment. The perceived tolerance of abusive language was a reason put forth in 2013 for the gender gap in Wikipedia editorship. Edit-a-thons have been held to encourage female editors and increase the coverage of women's topics.

In May 2018, a Wikipedia editor rejected a submitted article about Donna Strickland due to lack of coverage in the media. Five months later, Strickland won a Nobel Prize in Physics "for groundbreaking inventions in the field of laser physics", becoming the third woman to ever receive the award. Prior to winning the award, Strickland's only mention on Wikipedia was in the article about her collaborator and co-winner of the award Gérard Mourou. Her exclusion from Wikipedia led to accusations of sexism, but Corinne Purtill writing for Quartz argued that "it's also a pointed lesson in the hazards of gender bias in media, and of the broader consequences of underrepresentation." Purtill attributes the issue to the gender bias in media coverage.

A comprehensive 2008 survey, published in 2016, by Julia B. Bear of Stony Brook University's College of Business and Benjamin Collier of Carnegie Mellon University found significant gender differences in confidence in expertise, discomfort with editing, and response to critical feedback. "Women reported less confidence in their expertise, expressed greater discomfort with editing (which typically involves conflict), and reported more negative responses to critical feedback compared to men."

Operation

Wikimedia Foundation and affiliate movements

Katherine Maher in 2016. She is seen with light skin, blonde hair, and blue eyes. She is seen wearing a black shirt.
Katherine Maher, the third executive director of Wikimedia, served from 2016 to 2021

Wikipedia is hosted and funded by the Wikimedia Foundation, a non-profit organization which also operates Wikipedia-related projects such as Wiktionary and Wikibooks. The foundation relies on public contributions and grants to fund its mission. The foundation's 2020 Internal Revenue Service Form 990 shows revenue of $124.6 million and expenses of almost $112.2 million, with assets of about $191.2 million and liabilities of almost $11 million.

In May 2014, Wikimedia Foundation named Lila Tretikov as its second executive director, taking over for Sue Gardner. The Wall Street Journal reported on May 1, 2014, that Tretikov's information technology background from her years at University of California offers Wikipedia an opportunity to develop in more concentrated directions guided by her often repeated position statement that, "Information, like air, wants to be free." The same Wall Street Journal article reported these directions of development according to an interview with spokesman Jay Walsh of Wikimedia, who "said Tretikov would address that issue (paid advocacy) as a priority. 'We are really pushing toward more transparency ... We are reinforcing that paid advocacy is not welcome.' Initiatives to involve greater diversity of contributors, better mobile support of Wikipedia, new geo-location tools to find local content more easily, and more tools for users in the second and third world are also priorities", Walsh said.

Following the departure of Tretikov from Wikipedia due to issues concerning the use of the "superprotection" feature which some language versions of Wikipedia have adopted, Katherine Maher became the third executive director of the Wikimedia Foundation in June 2016. Maher stated that one of her priorities would be the issue of editor harassment endemic to Wikipedia as identified by the Wikipedia board in December. She said to Bloomberg Businessweek regarding the harassment issue that: "It establishes a sense within the community that this is a priority ... [and that correction requires that] it has to be more than words."

Maher served as executive director until April 2021. Maryana Iskander was named the incoming CEO in September 2021, and took over that role in January 2022. She stated that one of her focuses would be increasing diversity in the Wikimedia community.

Wikipedia is also supported by many organizations and groups that are affiliated with the Wikimedia Foundation but independently-run, called Wikimedia movement affiliates. These include Wikimedia chapters (which are national or sub-national organizations, such as Wikimedia Deutschland and Wikimedia France), thematic organizations (such as Amical Wikimedia for the Catalan language community), and user groups. These affiliates participate in the promotion, development, and funding of Wikipedia.

Software operations and support

The operation of Wikipedia depends on MediaWiki, a custom-made, free and open source wiki software platform written in PHP and built upon the MySQL database system. The software incorporates programming features such as a macro language, variables, a transclusion system for templates, and URL redirection. MediaWiki is licensed under the GNU General Public License (GPL) and it is used by all Wikimedia projects, as well as many other wiki projects. Originally, Wikipedia ran on UseModWiki written in Perl by Clifford Adams (Phase I), which initially required CamelCase for article hyperlinks; the present double bracket style was incorporated later. Starting in January 2002 (Phase II), Wikipedia began running on a PHP wiki engine with a MySQL database; this software was custom-made for Wikipedia by Magnus Manske. The Phase II software was repeatedly modified to accommodate the exponentially increasing demand. In July 2002 (Phase III), Wikipedia shifted to the third-generation software, MediaWiki, originally written by Lee Daniel Crocker.

Several MediaWiki extensions are installed to extend the functionality of the MediaWiki software.

In April 2005, a Lucene extension was added to MediaWiki's built-in search and Wikipedia switched from MySQL to Lucene for searching. Lucene was later replaced by CirrusSearch which is based on Elasticsearch.

In July 2013, after extensive beta testing, a WYSIWYG (What You See Is What You Get) extension, VisualEditor, was opened to public use. It was met with much rejection and criticism, and was described as "slow and buggy". The feature was changed from opt-out to opt-in afterward.

Automated editing

Wiki translation AI

Computer programs called bots have often been used to perform simple and repetitive tasks, such as correcting common misspellings and stylistic issues, or to start articles such as geography entries in a standard format from statistical data. One controversial contributor, Sverker Johansson, created articles with his bot Lsjbot, which was reported to create up to 10,000 articles on the Swedish Wikipedia on certain days. Additionally, there are bots designed to automatically notify editors when they make common editing errors (such as unmatched quotes or unmatched parentheses). Edits falsely identified by bots as the work of a banned editor can be restored by other editors. An anti-vandal bot is programmed to detect and revert vandalism quickly. Bots are able to indicate edits from particular accounts or IP address ranges, as occurred at the time of the shooting down of the MH17 jet in July 2014 when it was reported that edits were made via IPs controlled by the Russian government. Bots on Wikipedia must be approved before activation.

According to Andrew Lih, the current expansion of Wikipedia to millions of articles would be difficult to envision without the use of such bots.

Hardware operations and support

As of 2021, page requests are first passed to a front-end layer of Varnish caching servers and back-end layer caching is done by Apache Traffic Server. Requests that cannot be served from the Varnish cache are sent to load-balancing servers running the Linux Virtual Server software, which in turn pass them to one of the Apache web servers for page rendering from the database. The web servers deliver pages as requested, performing page rendering for all the language editions of Wikipedia. To increase speed further, rendered pages are cached in a distributed memory cache until invalidated, allowing page rendering to be skipped entirely for most common page accesses.

Diagram showing flow of data between Wikipedia's servers.
Overview of system architecture as of April 2020

Wikipedia currently runs on dedicated clusters of Linux servers running the Debian operating system. As of February 2023, caching clusters are located in Amsterdam, San Francisco, Singapore, and Marseille. By January 22, 2013, Wikipedia had migrated its primary data center to an Equinix facility in Ashburn, Virginia. In 2017, Wikipedia installed a caching cluster in an Equinix facility in Singapore, the first of its kind in Asia. In 2022, a caching data center was opened in Marseille, France.

Internal research and operational development

Following growing amounts of incoming donations in 2013 exceeding seven digits, the Foundation has reached a threshold of assets which qualify its consideration under the principles of industrial organization economics to indicate the need for the re-investment of donations into the internal research and development of the Foundation. Two projects of such internal research and development have been the creation of a Visual Editor and the "Thank" tab in the edit history, which were developed to improve issues of editor attrition. The estimates for reinvestment by industrial organizations into internal research and development was studied by Adam Jaffe, who recorded that the range of 4% to 25% annually was to be recommended, with high-end technology requiring the higher level of support for internal reinvestment. At the 2013 level of contributions for Wikimedia presently documented as 45 million dollars, the computed budget level recommended by Jaffe for reinvestment into internal research and development is between 1.8 million and 11.3 million dollars annually. In 2019, the level of contributions were reported by the Wikimedia Foundation as being at $120 million annually, updating the Jaffe estimates for the higher level of support to between $3.08 million and $19.2 million annually.

Internal news publications

Multiple Wikimedia projects have internal news publications. Wikimedia's online newspaper The Signpost was founded in 2005 by Michael Snow, a Wikipedia administrator who would join the Wikimedia Foundation's board of trustees in 2008. The publication covers news and events from the English Wikipedia, the Wikimedia Foundation, and Wikipedia's sister projects. Other past and present community news publications on English Wikipedia include the Wikiworld webcomic, the Wikipedia Weekly podcast, and newsletters of specific WikiProjects like The Bugle from WikiProject Military History and the monthly newsletter from The Guild of Copy Editors. There are also several publications from the Wikimedia Foundation and multilingual publications such as Wikimedia Diff and This Month in Education.

The Wikipedia Library

Wikipedia Library

The Wikipedia Library is a resource for Wikipedia editors which provides free access to a wide range of digital publications, so that they can consult and cite these while editing the encyclopedia. Over 60 publishers have partnered with The Wikipedia Library to provide access to their resources: when ICE Publishing joined in 2020, a spokesman said "By enabling free access to our content for Wikipedia editors, we hope to further the research community's resources – creating and updating Wikipedia entries on civil engineering which are read by thousands of monthly readers."

Access to content

Content licensing

When the project was started in 2001, all text in Wikipedia was covered by the GNU Free Documentation License (GFDL), a copyleft license permitting the redistribution, creation of derivative works, and commercial use of content while authors retain copyright of their work. The GFDL was created for software manuals that come with free software programs licensed under the GPL. This made it a poor choice for a general reference work: for example, the GFDL requires the reprints of materials from Wikipedia to come with a full copy of the GFDL text. In December 2002, the Creative Commons license was released; it was specifically designed for creative works in general, not just for software manuals. The Wikipedia project sought the switch to the Creative Commons. Because the GFDL and Creative Commons were incompatible, in November 2008, following the request of the project, the Free Software Foundation (FSF) released a new version of the GFDL designed specifically to allow Wikipedia to relicense its content to CC BY-SA by August 1, 2009. In April 2009, Wikipedia and its sister projects held a community-wide referendum which decided the switch in June 2009.

The handling of media files (e.g. image files) varies across language editions. Some language editions, such as the English Wikipedia, include non-free image files under fair use doctrine, while the others have opted not to, in part because of the lack of fair use doctrines in their home countries (e.g. in Japanese copyright law). Media files covered by free content licenses (e.g. Creative Commons' CC BY-SA) are shared across language editions via Wikimedia Commons repository, a project operated by the Wikimedia Foundation. Wikipedia's accommodation of varying international copyright laws regarding images has led some to observe that its photographic coverage of topics lags behind the quality of the encyclopedic text.

The Wikimedia Foundation is not a licensor of content on Wikipedia or its related projects but merely a hosting service for contributors to and licensors of Wikipedia, a position which was successfully defended in 2004 in a court in France.

Methods of access

Because Wikipedia content is distributed under an open license, anyone can reuse or re-distribute it at no charge. The content of Wikipedia has been published in many forms, both online and offline, outside the Wikipedia website.

Thousands of "mirror sites" exist that republish content from Wikipedia; two prominent ones that also include content from other reference sources are Reference.com and Answers.com. Another example is Wapedia, which began to display Wikipedia content in a mobile-device-friendly format before Wikipedia itself did. Some web search engines make special use of Wikipedia content when displaying search results: examples include Microsoft Bing (via technology gained from Powerset) and DuckDuckGo.

Collections of Wikipedia articles have been published on optical discs. An English version released in 2006 contained about 2,000 articles. The Polish-language version from 2006 contains nearly 240,000 articles, the German-language version from 2007/2008 contains over 620,000 articles, and the Spanish-language version from 2011 contains 886,000 articles. Additionally, "Wikipedia for Schools", the Wikipedia series of CDs / DVDs produced by Wikipedia and SOS Children, is a free selection from Wikipedia designed for education towards children eight to seventeen.

There have been efforts to put a select subset of Wikipedia's articles into printed book form. Since 2009, tens of thousands of print-on-demand books that reproduced English, German, Russian, and French Wikipedia articles have been produced by the American company Books LLC and by three Mauritian subsidiaries of the German publisher VDM.

The website DBpedia, begun in 2007, extracts data from the infoboxes and category declarations of the English-language Wikipedia. Wikimedia has created the Wikidata project with a similar objective of storing the basic facts from each page of Wikipedia and other Wikimedia Foundation projects and make it available in a queryable semantic format, RDF. As of February 2023, it has over 101 million items. WikiReader is a dedicated reader device that contains an offline copy of Wikipedia, which was launched by OpenMoko and first released in 2009.

Obtaining the full contents of Wikipedia for reuse presents challenges, since direct cloning via a web crawler is discouraged. Wikipedia publishes "dumps" of its contents, but these are text-only; as of 2023, there is no dump available of Wikipedia's images. Wikimedia Enterprise is a for-profit solution to this.

Several languages of Wikipedia also maintain a reference desk, where volunteers answer questions from the general public. According to a study by Pnina Shachaf in the Journal of Documentation, the quality of the Wikipedia reference desk is comparable to a standard library reference desk, with an accuracy of 55 percent.

Mobile access

A mobile version showing the English Wikipedia's Main Page, on August 3, 2019

Wikipedia's original medium was for users to read and edit content using any standard web browser through a fixed Internet connection. Although Wikipedia content has been accessible through the mobile web since July 2013, The New York Times on February 9, 2014, quoted Erik Möller, deputy director of the Wikimedia Foundation, stating that the transition of internet traffic from desktops to mobile devices was significant and a cause for concern and worry. The article in The New York Times reported the comparison statistics for mobile edits stating that, "Only 20 percent of the readership of the English-language Wikipedia comes via mobile devices, a figure substantially lower than the percentage of mobile traffic for other media sites, many of which approach 50 percent. And the shift to mobile editing has lagged even more." The New York Times reports that Möller has assigned "a team of 10 software developers focused on mobile", out of a total of approximately 200 employees working at the Wikimedia Foundation. One principal concern cited by The New York Times for the "worry" is for Wikipedia to effectively address attrition issues with the number of editors which the online encyclopedia attracts to edit and maintain its content in a mobile access environment.

Bloomberg Businessweek reported in July 2014 that Google's Android mobile apps have dominated the largest share of global smartphone shipments for 2013, with 78.6% of market share over their next closest competitor in iOS with 15.2% of the market. At the time of the appointment of new Wikimedia Foundation executive Lila Tretikov, Wikimedia representatives made a technical announcement concerning the number of mobile access systems in the market seeking access to Wikipedia. Soon after, the representatives stated that Wikimedia would be applying an all-inclusive approach to accommodate as many mobile access systems as possible in its efforts for expanding general mobile access, including BlackBerry and the Windows Phone system, making market share a secondary issue. The Android app for Wikipedia was released on July 23, 2014, to over 500,000 installs and generally positive reviews, scoring over four of a possible five in a poll of approximately 200,000 users downloading from Google. The version for iOS was released on April 3, 2013, to similar reviews.

Access to Wikipedia from mobile phones was possible as early as 2004, through the Wireless Application Protocol (WAP), via the Wapedia service. In June 2007, Wikipedia launched en.mobile.wikipedia.org, an official website for wireless devices. In 2009, a newer mobile service was officially released, located at en.m.wikipedia.org, which caters to more advanced mobile devices such as the iPhone, Android-based devices, or WebOS-based devices. Several other methods of mobile access to Wikipedia have emerged since. Many devices and applications optimize or enhance the display of Wikipedia content for mobile devices, while some also incorporate additional features such as use of Wikipedia metadata like geoinformation.

Wikipedia Zero was an initiative of the Wikimedia Foundation to expand the reach of the encyclopedia to the developing countries by partnering with mobile operators to allow free access. It was discontinued in February 2018 due to lack of participation from mobile operators.

Andrew Lih and Andrew Brown both maintain editing Wikipedia with smartphones is difficult and this discourages new potential contributors. Lih states that the number of Wikipedia editors has been declining after several years, and Tom Simonite of MIT Technology Review claims the bureaucratic structure and rules are a factor in this. Simonite alleges some Wikipedians use the labyrinthine rules and guidelines to dominate others and those editors have a vested interest in keeping the status quo. Lih alleges there is a serious disagreement among existing contributors on how to resolve this. Lih fears for Wikipedia's long-term future while Brown fears problems with Wikipedia will remain and rival encyclopedias will not replace it.

Chinese access

Access to the Chinese Wikipedia has been blocked in mainland China since May 2015. This was done after Wikipedia started to use HTTPS encryption, which made selective censorship more difficult.

Copycats

Russians have developed clones called Runiversalis and Ruwiki. Iranians have created a new website called wikisa.org.

Cultural influence

Trusted source to combat fake news

In 2017–18, after a barrage of false news reports, both Facebook and YouTube announced they would rely on Wikipedia to help their users evaluate reports and reject false news. Noam Cohen, writing in The Washington Post states, "YouTube's reliance on Wikipedia to set the record straight builds on the thinking of another fact-challenged platform, the Facebook social network, which announced last year that Wikipedia would help its users root out 'fake news'."

Readership

In February 2014, The New York Times reported that Wikipedia was ranked fifth globally among all websites, stating "With 18 billion page views and nearly 500 million unique visitors a month, ... Wikipedia trails just Yahoo, Facebook, Microsoft and Google, the largest with 1.2 billion unique visitors." However, its ranking dropped to 13th globally by June 2020 due mostly to a rise in popularity of Chinese websites for online shopping. The website has since recovered its ranking as of April 2022.

In addition to logistic growth in the number of its articles, Wikipedia has steadily gained status as a general reference website since its inception in 2001. The number of readers of Wikipedia worldwide reached 365 million at the end of 2009. The Pew Internet and American Life project found that one third of US Internet users consulted Wikipedia. In 2011, Business Insider gave Wikipedia a valuation of $4 billion if it ran advertisements.

According to "Wikipedia Readership Survey 2011", the average age of Wikipedia readers is 36, with a rough parity between genders. Almost half of Wikipedia readers visit the site more than five times a month, and a similar number of readers specifically look for Wikipedia in search engine results. About 47 percent of Wikipedia readers do not realize that Wikipedia is a non-profit organization.

As of February 2023, Wikipedia attracts around 2 billion unique devices monthly, with the English Wikipedia receiving 10 billion pageviews each month.

COVID-19 pandemic

During the COVID-19 pandemic, Wikipedia's coverage of the pandemic and fight against misinformation received international media attention, and brought an increase in Wikipedia readership overall. Noam Cohen wrote in Wired that Wikipedia's effort to combat misinformation related to the pandemic was different from other major websites, opining, "Unless Twitter, Facebook and the others can learn to address misinformation more effectively, Wikipedia will remain the last best place on the Internet." In October 2020, the World Health Organization announced they were freely licensing its infographics and other materials on Wikimedia projects. There were nearly 7,000 COVID-19 related Wikipedia articles across 188 different Wikipedias, as of November 2021.

Cultural significance

Wikipedia Monument in Słubice, Poland, by Mihran Hakobyan (2014)

Wikipedia's content has also been used in academic studies, books, conferences, and court cases. The Parliament of Canada's website refers to Wikipedia's article on same-sex marriage in the "related links" section of its "further reading" list for the Civil Marriage Act. The encyclopedia's assertions are increasingly used as a source by organizations such as the US federal courts and the World Intellectual Property Organization—though mainly for supporting information rather than information decisive to a case. Content appearing on Wikipedia has also been cited as a source and referenced in some US intelligence agency reports. In December 2008, the scientific journal RNA Biology launched a new section for descriptions of families of RNA molecules and requires authors who contribute to the section to also submit a draft article on the RNA family for publication in Wikipedia.

Wikipedia has also been used as a source in journalism, often without attribution, and several reporters have been dismissed for plagiarizing from Wikipedia.

In 2006, Time magazine recognized Wikipedia's participation (along with YouTube, Reddit, MySpace, and Facebook) in the rapid growth of online collaboration and interaction by millions of people worldwide. On September 16, 2007, The Washington Post reported that Wikipedia had become a focal point in the 2008 US election campaign, saying: "Type a candidate's name into Google, and among the first results is a Wikipedia page, making those entries arguably as important as any ad in defining a candidate. Already, the presidential entries are being edited, dissected and debated countless times each day." An October 2007 Reuters article, titled "Wikipedia page the latest status symbol", reported the recent phenomenon of how having a Wikipedia article vindicates one's notability.

One of the first times Wikipedia was involved in a governmental affair was on September 28, 2007, when Italian politician Franco Grillini raised a parliamentary question with the minister of cultural resources and activities about the necessity of freedom of panorama. He said that the lack of such freedom forced Wikipedia, "the seventh most consulted website", to forbid all images of modern Italian buildings and art, and claimed this was hugely damaging to tourist revenues.

Jimmy Wales accepts the 2008 Quadriga A Mission of Enlightenment award on behalf of Wikipedia

A working group led by Peter Stone (formed as a part of the Stanford-based project One Hundred Year Study on Artificial Intelligence) in its report called Wikipedia "the best-known example of crowdsourcing ... that far exceeds traditionally-compiled information sources, such as encyclopedias and dictionaries, in scale and depth".

In a 2017 opinion piece for Wired, Hossein Derakhshan describes Wikipedia as "one of the last remaining pillars of the open and decentralized web" and contrasted its existence as a text-based source of knowledge with social media and social networking services, the latter having "since colonized the web for television's values". For Derakhshan, Wikipedia's goal as an encyclopedia represents the Age of Enlightenment tradition of rationality triumphing over emotions, a trend which he considers "endangered" due to the "gradual shift from a typographic culture to a photographic one, which in turn mean[s] a shift from rationality to emotions, exposition to entertainment". Rather than "sapere aude" (lit.'dare to know'), social networks have led to a culture of "dare not to care to know". This is while Wikipedia faces "a more concerning problem" than funding, namely "a flattening growth rate in the number of contributors to the website". Consequently, the challenge for Wikipedia and those who use it is to "save Wikipedia and its promise of a free and open collection of all human knowledge amid the conquest of new and old television—how to collect and preserve knowledge when nobody cares to know."

Awards

Wikipedia team visiting the Parliament of Asturias
Wikipedians meeting after the 2015 Asturias awards ceremony

Wikipedia has won many awards, receiving its first two major awards in May 2004. The first was a Golden Nica for Digital Communities of the annual Prix Ars Electronica contest; this came with a €10,000 (£6,588; $12,700) grant and an invitation to present at the PAE Cyberarts Festival in Austria later that year. The second was a Judges' Webby Award for the "community" category.

In 2007, readers of brandchannel.com voted Wikipedia as the fourth-highest brand ranking, receiving 15 percent of the votes in answer to the question "Which brand had the most impact on our lives in 2006?"

In September 2008, Wikipedia received Quadriga A Mission of Enlightenment award of Werkstatt Deutschland along with Boris Tadić, Eckart Höfling, and Peter Gabriel. The award was presented to Wales by David Weinberger.

In 2015, Wikipedia was awarded both the annual Erasmus Prize, which recognizes exceptional contributions to culture, society or social sciences, and the Spanish Princess of Asturias Award on International Cooperation. Speaking at the Asturian Parliament in Oviedo, the city that hosts the awards ceremony, Jimmy Wales praised the work of the Asturian Wikipedia users.

Satire

Many parodies target Wikipedia's openness and susceptibility to inserted inaccuracies, with characters vandalizing or modifying the online encyclopedia project's articles.

Comedian Stephen Colbert has parodied or referenced Wikipedia on numerous episodes of his show The Colbert Report and coined the related term wikiality, meaning "together we can create a reality that we all agree on—the reality we just agreed on". Another example can be found in "Wikipedia Celebrates 750 Years of American Independence", a July 2006 front-page article in The Onion, as well as the 2010 The Onion article "'L.A. Law' Wikipedia Page Viewed 874 Times Today".

In an April 2007 episode of the American television comedy The Office, office manager (Michael Scott) is shown relying on a hypothetical Wikipedia article for information on negotiation tactics to assist him in negotiating lesser pay for an employee. Viewers of the show tried to add the episode's mention of the page as a section of the actual Wikipedia article on negotiation, but this effort was prevented by other users on the article's talk page.

"My Number One Doctor", a 2007 episode of the television show Scrubs, played on the perception that Wikipedia is an unreliable reference tool with a scene in which Perry Cox reacts to a patient who says that a Wikipedia article indicates that the raw food diet reverses the effects of bone cancer by retorting that the same editor who wrote that article also wrote the Battlestar Galactica episode guide.

In 2008, the comedy website CollegeHumor produced a video sketch named "Professor Wikipedia", in which the fictitious Professor Wikipedia instructs a class with a medley of unverifiable and occasionally absurd statements.

The Dilbert comic strip from May 8, 2009, features a character supporting an improbable claim by saying "Give me ten minutes and then check Wikipedia."

In July 2009, BBC Radio 4 broadcast a comedy series called Bigipedia, which was set on a website which was a parody of Wikipedia. Some of the sketches were directly inspired by Wikipedia and its articles.

On August 23, 2013, the New Yorker website published a cartoon with this caption: "Dammit, Manning, have you considered the pronoun war that this is going to start on your Wikipedia page?" The cartoon referred to Chelsea Elizabeth Manning (born Bradley Edward Manning), an American activist, politician, and former United States Army soldier who had recently come out as a trans woman.

In December 2015, John Julius Norwich stated, in a letter published in The Times newspaper, that as a historian he resorted to Wikipedia "at least a dozen times a day", and had never yet caught it out. He described it as "a work of reference as useful as any in existence", with so wide a range that it is almost impossible to find a person, place, or thing that it has left uncovered and that he could never have written his last two books without it.

Sister projects – Wikimedia

Wikipedia has spawned several sister projects, which are also wikis run by the Wikimedia Foundation. These other Wikimedia projects include Wiktionary, a dictionary project launched in December 2002, Wikiquote, a collection of quotations created a week after Wikimedia launched, Wikibooks, a collection of collaboratively written free textbooks and annotated texts, Wikimedia Commons, a site devoted to free-knowledge multimedia, Wikinews, for collaborative journalism, and Wikiversity, a project for the creation of free learning materials and the provision of online learning activities. Another sister project of Wikipedia, Wikispecies, is a catalogue of all species, but is not open for public editing. In 2012, Wikivoyage, an editable travel guide, and Wikidata, an editable knowledge base, launched.

Publishing

A group of Wikimedians of the Wikimedia DC chapter at the 2013 DC Wikimedia annual meeting standing in front of the Encyclopædia Britannica (back left) at the US National Archives

The most obvious economic effect of Wikipedia has been the death of commercial encyclopedias, especially printed versions like Encyclopædia Britannica, which were unable to compete with a product that is essentially free. Nicholas Carr's 2005 essay "The amorality of Web 2.0" criticizes websites with user-generated content (like Wikipedia) for possibly leading to professional (and, in his view, superior) content producers' going out of business, because "free trumps quality all the time". Carr wrote, "Implicit in the ecstatic visions of Web 2.0 is the hegemony of the amateur. I for one can't imagine anything more frightening." Others dispute the notion that Wikipedia, or similar efforts, will entirely displace traditional publications. Chris Anderson, the former editor-in-chief of Wired, wrote in Nature that the "wisdom of crowds" approach of Wikipedia will not displace top scientific journals with rigorous peer review processes.

Wikipedia's influence on the biography publishing business has been a concern for some. Book publishing data tracker Nielsen BookScan stated in 2013 that biography sales were dropping "far more sharply". Kathryn Hughes, professor of life writing at the University of East Anglia and author of two biographies wrote, "The worry is that, if you can get all that information from Wikipedia, what's left for biography?"

Research use

Wikipedia has been widely used as a corpus for linguistic research in computational linguistics, information retrieval and natural language processing. In particular, it commonly serves as a target knowledge base for the entity linking problem, which is then called "wikification", and to the related problem of word-sense disambiguation. Methods similar to wikification can in turn be used to find "missing" links in Wikipedia.

In 2015, French researchers José Lages of the University of Franche-Comté in Besançon and Dima Shepelyansky of Paul Sabatier University in Toulouse published a global university ranking based on Wikipedia scholarly citations. They used PageRank, CheiRank and similar algorithms "followed by the number of appearances in the 24 different language editions of Wikipedia (descending order) and the century in which they were founded (ascending order)". The study was updated in 2019.

A 2017 MIT study suggests that words used on Wikipedia articles end up in scientific publications.

Studies related to Wikipedia have been using machine learning and artificial intelligence to support various operations. One of the most important areas is the automatic detection of vandalism and data quality assessment in Wikipedia.

In February 2022, civil servants from the UK's Department for Levelling Up, Housing and Communities were found to have used Wikipedia for research in the drafting of the Levelling Up White Paper after journalists at The Independent noted that parts of the document had been lifted directly from Wikipedia articles on Constantinople and the list of largest cities throughout history.

Related projects

Several interactive multimedia encyclopedias incorporating entries written by the public existed long before Wikipedia was founded. The first of these was the 1986 BBC Domesday Project, which included text (entered on BBC Micro computers) and photographs from more than a million contributors in the UK, and covered the geography, art, and culture of the UK. This was the first interactive multimedia encyclopedia (and was also the first major multimedia document connected through internal links), with the majority of articles being accessible through an interactive map of the UK. The user interface and part of the content of the Domesday Project were emulated on a website until 2008.

Several free-content, collaborative encyclopedias were created around the same period as Wikipedia (e.g. Everything2), with many later being merged into the project (e.g. GNE). One of the most successful early online encyclopedias incorporating entries by the public was h2g2, which was created by Douglas Adams in 1999. The h2g2 encyclopedia is relatively lighthearted, focusing on articles which are both witty and informative.

Subsequent collaborative knowledge websites have drawn inspiration from Wikipedia. Others use more traditional peer review, such as Encyclopedia of Life and the online wiki encyclopedias Scholarpedia and Citizendium. The latter was started by Sanger in an attempt to create a reliable alternative to Wikipedia.

Interoperability

From Wikipedia, the free encyclopedia
An example of software interoperability: a mobile device and a TV device both playing the same digital music file that is stored on a server off-screen in the home network

Interoperability is a characteristic of a product or system to work with other products or systems. While the term was initially defined for information technology or systems engineering services to allow for information exchange, a broader definition takes into account social, political, and organizational factors that impact system-to-system performance.

Types of interoperability include syntactic interoperability, where two systems can communicate with each other, and cross-domain interoperability, where multiple organizations work together and exchange information.

Types

If two or more systems use common data formats and communication protocols then they are capable of communicating with each other and they exhibit syntactic interoperability. XML and SQL are examples of common data formats and protocols. Low-level data formats also contribute to syntactic interoperability, ensuring that alphabetical characters are stored in the same ASCII or a Unicode format in all the communicating systems.

Beyond the ability of two or more computer systems to exchange information, semantic interoperability is the ability to automatically interpret the information exchanged meaningfully and accurately in order to produce useful results as defined by the end users of both systems. To achieve semantic interoperability, both sides must refer to a common information exchange reference model. The content of the information exchange requests are unambiguously defined: what is sent is the same as what is understood.

Cross-domain interoperability involves multiple social, organizational, political, legal entities working together for a common interest or information exchange.

Interoperability and open standards

Interoperability implies exchanges between a range of products, or similar products from several different vendors, or even between past and future revisions of the same product. Interoperability may be developed post-facto, as a special measure between two products, while excluding the rest, by using open standards. When a vendor is forced to adapt its system to a dominant system that is not based on Open standards, it is compatibility, not interoperability.

Open standards

Open standards rely on a broadly consultative and inclusive group including representatives from vendors, academics and others holding a stake in the development that discusses and debate the technical and economic merits, demerits and feasibility of a proposed common protocol. After the doubts and reservations of all members are addressed, the resulting common document is endorsed as a common standard. This document may be subsequently released to the public, and henceforth becomes an open standard. It is usually published and is available freely or at a nominal cost to any and all comers, with no further encumbrances. Various vendors and individuals (even those who were not part of the original group) can use the standards document to make products that implement the common protocol defined in the standard and are thus interoperable by design, with no specific liability or advantage for customers for choosing one product over another on the basis of standardized features. The vendors' products compete on the quality of their implementation, user interface, ease of use, performance, price, and a host of other factors, while keeping the customer's data intact and transferable even if he chooses to switch to another competing product for business reasons.

Post facto interoperability

Post facto interoperability may be the result of the absolute market dominance of a particular product in contravention of any applicable standards, or if any effective standards were not present at the time of that product's introduction. The vendor behind that product can then choose to ignore any forthcoming standards and not co-operate in any standardization process at all, using its near-monopoly to insist that its product sets the de facto standard by its very market dominance. This is not a problem if the product's implementation is open and minimally encumbered, but it may well be both closed and heavily encumbered (e.g. by patent claims). Because of the network effect, achieving interoperability with such a product is both critical for any other vendor if it wishes to remain relevant in the market, and difficult to accomplish because of lack of cooperation on equal terms with the original vendor, who may well see the new vendor as a potential competitor and threat. The newer implementations often rely on clean-room reverse engineering in the absence of technical data to achieve interoperability. The original vendors may provide such technical data to others, often in the name of encouraging competition, but such data is invariably encumbered, and may be of limited use. Availability of such data is not equivalent to an open standard, because:

  1. The data is provided by the original vendor on a discretionary basis, and the vendor has every interest in blocking the effective implementation of competing solutions, and may subtly alter or change its product, often in newer revisions, so that competitors' implementations are almost, but not quite completely interoperable, leading customers to consider them unreliable or of lower quality. These changes may not be passed on to other vendors at all, or passed on after a strategic delay, maintaining the market dominance of the original vendor.
  2. The data itself may be encumbered, e.g. by patents or pricing, leading to a dependence of all competing solutions on the original vendor, and possibly leading a revenue stream from the competitors' customers back to the original vendor. This revenue stream is the result of the original product's market dominance and not a result of any innate superiority.
  3. Even when the original vendor is genuinely interested in promoting a healthy competition (so that he may also benefit from the resulting innovative market), post-facto interoperability may often be undesirable as many defects or quirks can be directly traced back to the original implementation's technical limitations. Although in an open process, anyone may identify and correct such limitations, and the resulting cleaner specification may be used by all vendors, this is more difficult post-facto, as customers already have valuable information and processes encoded in the faulty but dominant product, and other vendors are forced to replicate those faults and quirks for the sake of preserving interoperability even if they could design better solutions. Alternatively, it can be argued that even open processes are subject to the weight of past implementations and imperfect past designs and that the power of the dominant vendor to unilaterally correct or improve the system and impose the changes to all users facilitates innovation.
  4. Lack of an open standard can also become problematic for the customers, as in the case of the original vendor's inability to fix a certain problem that is an artifact of technical limitations in the original product. The customer wants that fault fixed, but the vendor has to maintain that faulty state, even across newer revisions of the same product, because that behavior is a de facto standard and many more customers would have to pay the price of any interoperability issues caused by fixing the original problem and introducing new behavior.

Government

eGovernment

Speaking from an e-government perspective, interoperability refers to the collaboration ability of cross-border services for citizens, businesses and public administrations. Exchanging data can be a challenge due to language barriers, different specifications of formats, varieties of categorizations and other hindrances.

If data is interpreted differently, collaboration is limited, takes longer and is inefficient. For instance, if a citizen of country A wants to purchase land in country B, the person will be asked to submit the proper address data. Address data in both countries include full name details, street name and number as well as a postal code. The order of the address details might vary. In the same language, it is not an obstacle to order the provided address data; but across language barriers, it becomes difficult. If the language uses a different writing system it is almost impossible if no translation tools are available.

Flood risk management

Interoperability is used by researchers in the context of urban flood risk management.  Cities and urban areas worldwide are expanding, which creates complex spaces with many interactions between the environment, infrastructure and people.  To address this complexity and manage water in urban areas appropriately, a system of systems approach to water and flood control is necessary. In this context, interoperability is important to facilitate system-of-systems thinking, and is defined as: "the ability of any water management system to redirect water and make use of other system(s) to maintain or enhance its performance function during water exceedance events." By assessing the complex properties of urban infrastructure systems, particularly the interoperability between the drainage systems and other urban systems (e.g. infrastructure such as transport), it could be possible to expand the capacity of the overall system to manage flood water towards achieving improved urban flood resilience.

Military forces

Force interoperability is defined in NATO as the ability of the forces of two or more nations to train, exercise and operate effectively together in the execution of assigned missions and tasks. Additionally NATO defines interoperability more generally as the ability to act together coherently, effectively and efficiently to achieve Allied tactical, operational and strategic objectives.

At the strategic level, interoperability is an enabler for coalition building. It facilitates meaningful contributions by coalition partners. At this level, interoperability issues center on harmonizing world views, strategies, doctrines, and force structures. Interoperability is an element of coalition willingness to work together over the long term to achieve and maintain shared interests against common threats. Interoperability at the operational and tactical levels is where strategic interoperability and technological interoperability come together to help allies shape the environment, manage crises, and win wars. The benefits of interoperability at the operational and tactical levels generally derive from the interchangeability of force elements and units. Technological interoperability reflects the interfaces between organizations and systems. It focuses on communications and computers but also involves the technical capabilities of systems and the resulting mission compatibility between the systems and data of coalition partners. At the technological level, the benefits of interoperability come primarily from their impacts at the operational and tactical levels in terms of enhancing flexibility.

Public safety

Because first responders need to be able to communicate during wide-scale emergencies, interoperability is an important issue for law enforcement, fire fighting, emergency medical services, and other public health and safety departments. It has been a major area of investment and research over the last 12 years. Widely disparate and incompatible hardware impedes the exchange of information between agencies. Agencies' information systems such as computer-aided dispatch systems and records management systems functioned largely in isolation, in so-called information islands. Agencies tried to bridge this isolation with inefficient, stop-gap methods while large agencies began implementing limited interoperable systems. These approaches were inadequate and, in the US, the lack of interoperability in the public safety realm become evident during the 9/11 attacks on the Pentagon and World Trade Center structures. Further evidence of a lack of interoperability surfaced when agencies tackled the aftermath of Hurricane Katrina.

In contrast to the overall national picture, some states, including Utah, have already made great strides forward. The Utah Highway Patrol and other departments in Utah have created a statewide data sharing network.

The Commonwealth of Virginia is one of the leading states in the United States in improving interoperability. The Interoperability Coordinator leverages a regional structure to better allocate grant funding around the Commonwealth so that all areas have an opportunity to improve communications interoperability. Virginia's strategic plan for communications is updated yearly to include new initiatives for the Commonwealth – all projects and efforts are tied to this plan, which is aligned with the National Emergency Communications Plan, authored by the Department of Homeland Security's Office of Emergency Communications.

The State of Washington seeks to enhance interoperability statewide. The State Interoperability Executive Committee (SIEC), established by the legislature in 2003, works to assist emergency responder agencies (police, fire, sheriff, medical, hazmat, etc.) at all levels of government (city, county, state, tribal, federal) to define interoperability for their local region. Washington recognizes that collaborating on system design and development for wireless radio systems enables emergency responder agencies to efficiently provide additional services, increase interoperability, and reduce long-term costs. This work saves the lives of emergency personnel and the citizens they serve.

The U.S. government is making an effort to overcome the nation's lack of public safety interoperability. The Department of Homeland Security's Office for Interoperability and Compatibility (OIC) is pursuing the SAFECOM and CADIP and Project 25 programs, which are designed to help agencies as they integrate their CAD and other IT systems.

The OIC launched CADIP in August 2007. This project will partner the OIC with agencies in several locations, including Silicon Valley. This program will use case studies to identify the best practices and challenges associated with linking CAD systems across jurisdictional boundaries. These lessons will create the tools and resources public safety agencies can use to build interoperable CAD systems and communicate across local, state, and federal boundaries.

As regulator for interoperability

Governance entities can increase interoperability through their legislative and executive powers. For instance, in 2021 the European Commission, after commissioning two impact assessment studies and a technology analysis study, proposed the implementation of a standardization – for iterations of USB-C – of phone charger products, which may increase interoperability along with convergence and convenience for consumers while decreasing resource needs, redundancy and electronic waste.

Commerce and industries

Information technology and computers

Desktop

Desktop interoperability is a subset of software interoperability. In the early days, the focus of interoperability was to integrate web applications with other web applications. Over time, open-system containers were developed to create a virtual desktop environment in which these applications could be registered and then communicate with each other using simple publish–subscribe patterns. Rudimentary UI capabilities were also supported allowing windows to be grouped with other windows. Today, desktop interoperability has evolved into full-service platforms which include container support, basic exchange between web and web, but also native support for other application types and advanced window management. The very latest interop platforms also include application services such as universal search, notifications, user permissions and preferences, 3rd party application connectors and language adapters for in-house applications.

Information search

Search interoperability refers to the ability of two or more information collections to be searched by a single query.

Specifically related to web-based search, the challenge of interoperability stems from the fact designers of web resources typically have little or no need to concern themselves with exchanging information with other web resources. Federated Search technology, which does not place format requirements on the data owner, has emerged as one solution to search interoperability challenges. In addition, standards, such as Open Archives Initiative Protocol for Metadata Harvesting, Resource Description Framework, and SPARQL, have emerged that also help address the issue of search interoperability related to web resources. Such standards also address broader topics of interoperability, such as allowing data mining.

Software

Interoperability: playing the two role network game, when one of the player clients (top left) runs under Sun Microsystems and another under GNU Classpath with JamVM. The applications execute the same bytecode and interoperate using the standard RMI-IIOP messages for communication.

With respect to software, the term interoperability is used to describe the capability of different programs to exchange data via a common set of exchange formats, to read and write the same file formats, and to use the same communication protocols. The lack of interoperability can be a consequence of a lack of attention to standardization during the design of a program. Indeed, interoperability is not taken for granted in the non-standards-based portion of the computing world.

According to ISO/IEC 2382-01, Information Technology Vocabulary, Fundamental Terms, interoperability is defined as follows: "The capability to communicate, execute programs, or transfer data among various functional units in a manner that requires the user to have little or no knowledge of the unique characteristics of those units".

Standards-developing organizations provide open public software specifications to facilitate interoperability; examples include the Oasis-Open organization and buildingSMART (formerly the International Alliance for Interoperability). As far as user communities, Neutral Third Party is creating standards for business process interoperability. Another example of a neutral party is the RFC documents from the Internet Engineering Task Force (IETF).

The Open Service for Lifecycle Collaboration community is working on finding a common standard in order that software tools can share and exchange data e.g. bugs, tasks, requirements etc. The final goal is to agree on an open standard for interoperability of open source application lifecycle management tools.

Java is an example of an interoperable programming language that allows for programs to be written once and run anywhere with a Java virtual machine. A program in Java, so long as it does not use system-specific functionality, will maintain interoperability with all systems that have a Java virtual machine available. Applications will maintain compatibility because, while the implementation is different, the underlying language interfaces are the same.

Achieving software

Software interoperability is achieved through five interrelated ways:

  1. Product testing
    Products produced to a common standard, or to a sub-profile thereof, depend on the clarity of the standards, but there may be discrepancies in their implementations that system or unit testing may not uncover. This requires that systems formally be tested in a production scenario – as they will be finally implemented – to ensure they actually will intercommunicate as advertised, i.e. they are interoperable. Interoperable product testing is different from conformance-based product testing as conformance to a standard does not necessarily engender interoperability with another product which is also tested for conformance.
  2. Product engineering
    Implements the common standard, or a sub-profile thereof, as defined by the industry and community partnerships with the specific intention of achieving interoperability with other software implementations also following the same standard or sub-profile thereof.
  3. Industry and community partnership
    Industry and community partnerships, either domestic or international, sponsor standard workgroups with the purpose of defining a common standard that may be used to allow software systems to intercommunicate for a defined purpose. At times an industry or community will sub-profile an existing standard produced by another organization to reduce options and thus make interoperability more achievable for implementations.
  4. Common technology and intellectual property
    The use of a common technology or intellectual property may speed up and reduce the complexity of interoperability by reducing variability between components from different sets of separately developed software products and thus allowing them to intercommunicate more readily. This technique has some of the same technical results as using a common vendor product to produce interoperability. The common technology can come through third-party libraries or open-source developments.
  5. Standard implementation
    Software interoperability requires a common agreement that is normally arrived at via an industrial, national or international standard.

Each of these has an important role in reducing variability in intercommunication software and enhancing a common understanding of the end goal to be achieved.

Unified interoperability

Unified interoperability is the property of a system that allows for the integration of real-time and non-real time communications, activities, data, and information services (i.e., unified) and the display and coordination of those services across systems and devices (i.e., interoperability). Unified interoperability provides the capability to communicate and exchange processing across different applications, data, and infrastructure.

Market dominance and power

Interoperability tends to be regarded as an issue for experts and its implications for daily living are sometimes underrated. The European Union Microsoft competition case shows how interoperability concerns important questions of power relationships. In 2004, the European Commission found that Microsoft had abused its market power by deliberately restricting interoperability between Windows work group servers and non-Microsoft work group servers. By doing so, Microsoft was able to protect its dominant market position for work group server operating systems, the heart of corporate IT networks. Microsoft was ordered to disclose complete and accurate interface documentation, which could enable rival vendors to compete on an equal footing (the interoperability remedy).

Interoperability has also surfaced in the software patent debate in the European Parliament (June–July 2005). Critics claim that because patents on techniques required for interoperability are kept under RAND (reasonable and non-discriminatory licensing) conditions, customers will have to pay license fees twice: once for the product and, in the appropriate case, once for the patent-protected program the product uses.

Manufacturing

Interoperability has become a common challenge within the manufacturing field in recent years particularly due to legacy systems, and the integration of manufacturing processes under the directive of promoting Industry 4.0. Interoperability has become a cornerstone of manufacturing policy and directives alongside autonomy and sustainability which can be identified within the German Federal policy of 2030 Vision for Industrie 4.0. The current pressing challenge for interoperability is closely linked to that of standardization and the implementation of best practices, which have prevented the driving of I4.0 to link manufacturing throughout the supply chain. Research into the current challenges have indicated that there is a gap within the IT and application landscapes of manufacturing enterprises, which present challenges for the linking of systems and flow of data.

Business precesses

Interoperability is often more of an organizational issue. Interoperability can have a significant impact on the organizations concerned, raising issues of ownership (do people want to share their data? or are they dealing with information silos?), labor relations (are people prepared to undergo training?) and usability. In this context, a more apt definition is captured in the term business process interoperability.

Interoperability can have important economic consequences; for example, research has estimated the cost of inadequate interoperability in the U.S. capital facilities industry to be $15.8 billion a year. If competitors' products are not interoperable (due to causes such as patents, trade secrets or coordination failures), the result may well be monopoly or market failure. For this reason, it may be prudent for user communities or governments to take steps to encourage interoperability in various situations. At least 30 international bodies and countries have implemented eGovernment-based interoperability framework initiatives called e-GIF while in the United States there is the NIEM initiative.

Medical industry

New technology is being introduced in hospitals and labs at an ever-increasing rate. The need for plug-and-play interoperability – the ability to take a medical device out of its box and easily make it work with one's other devices – has attracted great attention from both healthcare providers and industry.

Increasingly, medical devices like incubators and imaging systems feature software that integrates at the point of care and with electronic systems, such as electronic medical records. At the 2016 Regulatory Affairs Professionals Society (RAPS) meeting, experts in the field like Angela N. Johnson with GE Healthcare and representative of the United States Food and Drug Administration provided practical seminars in how companies developing new medical devices, and hospitals installing them, can work more effectively to align interoperable software systems.

Railways

Railways have greater or lesser interoperability depending on conforming to standards of gauge, couplings, brakes, signalling, communications, loading gauge, structure gauge, and operating rules, to mention a few parameters. For passenger rail service, different railway platform height and width clearance standards may also cause interoperability problems.

North American freight and intercity passenger railroads are highly interoperable, but systems in Europe, Asia, Africa, Central and South America, and Australia are much less so. The parameter most difficult to overcome (at reasonable cost) is incompatibility of gauge, though variable gauge axle systems are increasingly used.

Telecommunications

In telecommunication, the term can be defined as:

  1. The ability to provide services to and accept services from other systems, and to use the services exchanged to enable them to operate effectively together. ITU-T provides standards for international telecommunications.
  2. The condition achieved among communications-electronics systems or items of communications-electronics equipment when information or services can be exchanged directly and satisfactorily between them and/or their users. The degree of interoperability should be defined when referring to specific cases.

In two-way radio, interoperability is composed of three dimensions:

  • compatible communications paths (compatible frequencies, equipment and signaling),
  • radio system coverage or adequate signal strength, and;
  • scalable capacity.

Organizations dedicated to interoperability

Many organizations are dedicated to interoperability. All have in common that they want to push the development of the World Wide Web towards the semantic web. Some concentrate on eGovernment, eBusiness or data exchange in general.

Global

Internationally, Network Centric Operations Industry Consortium facilitates global interoperability across borders, language and technical barriers. In the built environment, the International Alliance for Interoperability started in 1994, and was renamed buildingSMART in 2005.

Europe

In Europe, for instance, the European Commission and its IDABC program issue the European Interoperability Framework. IDABC was succeeded by the ISA program. They also initiated the Semantic Interoperability Centre Europe (SEMIC.EU). A European Land Information Service (EULIS) was established in 2006, as a consortium of European National Land Registers. The aim of the service is to establish a single portal through which customers are provided with access to information about individual properties, about land and property registration services, and about the associated legal environment.

The European Interoperability Framework (EIF)  considered four kinds of interoperability: 1) legal interoperability, 2) organizational interoperability, 3) semantic interoperability, and 4) technical interoperability. In the European Research Cluster on the Internet of Things (IERC) and IoT Semantic Interoperability Best Practices; four kinds of interoperability are distinguished: 1) syntactical interoperability, 2) technical interoperability, 3) semantic interoperability, and 4) organizational interoperability.

US

In the United States, the General Services Administration Component Organization and Registration Environment (CORE.GOV) initiative provided a collaboration environment for component development, sharing, registration, and reuse in the early 2000s. A related initiative is the ongoing National Information Exchange Model (NIEM) work and component repository. The National Institute of Standards and Technology serves as an agency for measurement standards.

API

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/API
Screenshot of web API documentation written by NASA

An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how to build or use such a connection or interface is called an API specification. A computer system that meets this standard is said to implement or expose an API. The term API may refer either to the specification or to the implementation. Whereas a system's user interface dictates how its end-users interact with the system in question, its API dictates how to write code that takes advantage of that system's capabilities.

In contrast to a user interface, which connects a computer to a person, an application programming interface connects computers or pieces of software to each other. It is not intended to be used directly by a person (the end user) other than a computer programmer who is incorporating it into the software. An API is often made up of different parts which act as tools or services that are available to the programmer. A program or a programmer that uses one of these parts is said to call that portion of the API. The calls that make up the API are also known as subroutines, methods, requests, or endpoints. An API specification defines these calls, meaning that it explains how to use or implement them.

One purpose of APIs is to hide the internal details of how a system works, exposing only those parts that a programmer will find useful, and keeping them consistent even if the internal details change later. An API may be custom-built for a particular pair of systems, or it may be a shared standard allowing interoperability among many systems.

There are APIs for programming languages, software libraries, computer operating systems, and computer hardware. APIs originated in the 1940s, though the term did not emerge until the 1960s and 1970s. Contemporary usage of the term API often refers to web APIs, which allow communication between computers that are joined by the internet. Recent developments in APIs have led to the rise in popularity of microservices, which are loosely coupled services accessed through public APIs.

Purpose

In building applications, an API simplifies programming by abstracting the underlying implementation and only exposing objects or actions the developer needs. While a graphical interface for an email client might provide a user with a button that performs all the steps for fetching and highlighting new emails, an API for file input/output might give the developer a function that copies a file from one location to another without requiring that the developer understand the file system operations occurring behind the scenes.

History of the term

A diagram from 1978 proposing the expansion of the idea of the API to become a general programming interface, beyond application programs alone

The term API initially described an interface only for end-user-facing programs, known as application programs. This origin is still reflected in the name "application programming interface." Today, the term is broader, including also utility software and even hardware interfaces.

1940s and 1950s

The idea of the API is much older than the term itself. British computer scientists Maurice Wilkes and David Wheeler worked on a modular software library in the 1940s for EDSAC, an early computer. The subroutines in this library were stored on punched paper tape organized in a filing cabinet. This cabinet also contained what Wilkes and Wheeler called a "library catalog" of notes about each subroutine and how to incorporate it into a program. Today, such a catalog would be called an API (or an API specification or API documentation) because it instructs a programmer on how to use (or "call") each subroutine that the programmer needs.

Wilkes and Wheeler's 1951 book The Preparation of Programs for an Electronic Digital Computer contains the first published API specification. Joshua Bloch considers that Wilkes and Wheeler "latently invented" the API because it is more of a concept that is discovered than invented.

Although the people who coined the term API were implementing software on a Univac 1108, the goal of their API was to make hardware independent programs possible.

1960s and 1970s

The term "application program interface" (without an ‑ing suffix) is first recorded in a paper called Data structures and techniques for remote computer graphics presented at an AFIPS conference in 1968. The authors of this paper use the term to describe the interaction of an application—a graphics program in this case—with the rest of the computer system. A consistent application interface (consisting of Fortran subroutine calls) was intended to free the programmer from dealing with idiosyncrasies of the graphics display device, and to provide hardware independence if the computer or the display were replaced.

The term was introduced to the field of databases by C. J. Date in a 1974 paper called The Relational and Network Approaches: Comparison of the Application Programming Interface. An API became a part of the ANSI/SPARC framework for database management systems. This framework treated the application programming interface separately from other interfaces, such as the query interface. Database professionals in the 1970s observed these different interfaces could be combined; a sufficiently rich application interface could support the other interfaces as well.

This observation led to APIs that supported all types of programming, not just application programming.

1990s

By 1990, the API was defined simply as "a set of services available to a programmer for performing certain tasks" by technologist Carl Malamud.

The idea of the API was expanded again with the dawn of remote procedure calls and web APIs. As computer networks became common in the 1970s and 1980s, programmers wanted to call libraries located not only on their local computers but on computers located elsewhere. These remote procedure calls were well supported by the Java language in particular. In the 1990s, with the spread of the internet, standards like CORBA, COM, and DCOM competed to become the most common way to expose API services.

2000s

Roy Fielding's dissertation Architectural Styles and the Design of Network-based Software Architectures at UC Irvine in 2000 outlined Representational state transfer (REST) and described the idea of a "network-based Application Programming Interface" that Fielding contrasted with traditional "library-based" APIs. XML and JSON web APIs saw widespread commercial adoption beginning in 2000 and continuing as of 2022. The web API is now the most common meaning of the term API.

The Semantic Web proposed by Tim Berners-Lee in 2001 included "semantic APIs" that recasts the API as an open, distributed data interface rather than a software behavior interface. Proprietary interfaces and agents became more widespread than open ones, but the idea of the API as a data interface took hold. Because web APIs are widely used to exchange data of all kinds online, API has become a broad term describing much of the communication on the internet. When used in this way, the term API has overlap in meaning with the term communication protocol.

Usage

Libraries and frameworks

The interface to a software library is one type of API. The API describes and prescribes the "expected behavior" (a specification) while the library is an "actual implementation" of this set of rules.

A single API can have multiple implementations (or none, being abstract) in the form of different libraries that share the same programming interface.

The separation of the API from its implementation can allow programs written in one language to use a library written in another. For example, because Scala and Java compile to compatible bytecode, Scala developers can take advantage of any Java API.

API use can vary depending on the type of programming language involved. An API for a procedural language such as Lua could consist primarily of basic routines to execute code, manipulate data or handle errors while an API for an object-oriented language, such as Java, would provide a specification of classes and its class methods. Hyrum's law states that "With a sufficient number of users of an API, it does not matter what you promise in the contract: all observable behaviors of your system will be depended on by somebody." Meanwhile, several studies show that most applications that use an API tend to use a small part of the API.

Language bindings are also APIs. By mapping the features and capabilities of one language to an interface implemented in another language, a language binding allows a library or service written in one language to be used when developing in another language.

Tools such as SWIG and F2PY, a Fortran-to-Python interface generator, facilitate the creation of such interfaces.

An API can also be related to a software framework: a framework can be based on several libraries implementing several APIs, but unlike the normal use of an API, the access to the behavior built into the framework is mediated by extending its content with new classes plugged into the framework itself.

Moreover, the overall program flow of control can be out of the control of the caller and in the framework's hands by inversion of control or a similar mechanism.

Operating systems

An API can specify the interface between an application and the operating system. POSIX, for example, provides a set of common API specifications that aim to enable an application written for a POSIX conformant operating system to be compiled for another POSIX conformant operating system.

Linux and Berkeley Software Distribution are examples of operating systems that implement the POSIX APIs.

Microsoft has shown a strong commitment to a backward-compatible API, particularly within its Windows API (Win32) library, so older applications may run on newer versions of Windows using an executable-specific setting called "Compatibility Mode".

An API differs from an application binary interface (ABI) in that an API is source code based while an ABI is binary based. For instance, POSIX provides APIs while the Linux Standard Base provides an ABI.

Remote APIs

Remote APIs allow developers to manipulate remote resources through protocols, specific standards for communication that allow different technologies to work together, regardless of language or platform. For example, the Java Database Connectivity API allows developers to query many different types of databases with the same set of functions, while the Java remote method invocation API uses the Java Remote Method Protocol to allow invocation of functions that operate remotely but appear local to the developer.

Therefore, remote APIs are useful in maintaining the object abstraction in object-oriented programming; a method call, executed locally on a proxy object, invokes the corresponding method on the remote object, using the remoting protocol, and acquires the result to be used locally as a return value.

A modification of the proxy object will also result in a corresponding modification of the remote object.

Web APIs

Web APIs are a service accessed from client devices (mobile phones, laptops, etc.) to a web server using the Hypertext Transfer Protocol (HTTP). Client devices send a request in the form of an HTTP request, and are met with a response message usually in JavaScript Object Notation (JSON) or Extensible Markup Language (XML) format. Developers typically use Web APIs to query a server for a specific set of data from that server.

An example might be a shipping company API that can be added to an eCommerce-focused website to facilitate ordering shipping services and automatically include current shipping rates, without the site developer having to enter the shipper's rate table into a web database. While "web API" historically has been virtually synonymous with web service, the recent trend (so-called Web 2.0) has been moving away from Simple Object Access Protocol (SOAP) based web services and service-oriented architecture (SOA) towards more direct representational state transfer (REST) style web resources and resource-oriented architecture (ROA). Part of this trend is related to the Semantic Web movement toward Resource Description Framework (RDF), a concept to promote web-based ontology engineering technologies. Web APIs allow the combination of multiple APIs into new applications known as mashups.

In the social media space, web APIs have allowed web communities to facilitate sharing content and data between communities and applications. In this way, content that is created in one place dynamically can be posted and updated to multiple locations on the web. For example, Twitter's REST API allows developers to access core Twitter data and the Search API provides methods for developers to interact with Twitter Search and trends data.

Design

The design of an API has a significant impact on its usage. First of all, the design of programming interfaces represents an important part of software architecture, the organization of a complex piece of software. The principle of information hiding describes the role of programming interfaces as enabling modular programming by hiding the implementation details of the modules so that users of modules need not understand the complexities inside the modules. Aside from the previous underlying principle, other metrics for measuring the usability of an API may include properties such as functional efficiency, overall correctness, and learnability for novices. One straightforward and commonly adopted way of designing APIs is to follow Nielsen's heuristic evaluation guidelines. The Factory method pattern is also typical in designing APIs due to their reusable nature. Thus, the design of an API attempts to provide only the tools a user would expect.

Synchronous versus asynchronous

An application programming interface can be synchronous or asynchronous. A synchronous API call is a design pattern where the call site is blocked while waiting for the called code to finish. With an asynchronous API call, however, the call site is not blocked while waiting for the called code to finish, and instead the calling thread is notified when the reply arrives.

Security

API security is very critical when developing a public facing API. Common threats include SQL injection, Denial-of-service attack (DoS), broken authentication, and exposing sensitive data. Without ensuring proper security practices bad actors can get access to information they should not have or even gain privileges to make changes to your server. Some common security practices include proper connection security using HTTPS, content security to mitigate data injection attacks, and requiring an API key to use your service. Many public facing API services require you to use an assigned API key, and will refuse to serve data without sending the key with your request.

Release policies

APIs are one of the more common ways technology companies integrate. Those that provide and use APIs are considered as being members of a business ecosystem.

The main policies for releasing an API are:

  • Private: The API is for internal company use only.
  • Partner: Only specific business partners can use the API. For example, vehicle for hire companies such as Uber and Lyft allow approved third-party developers to directly order rides from within their apps. This allows the companies to exercise quality control by curating which apps have access to the API and provides them with an additional revenue stream.
  • Public: The API is available for use by the public. For example, Microsoft makes the Windows API public, and Apple releases its API Cocoa so that software can be written for their platforms. Not all public APIs are generally accessible by everybody. For example, Internet service providers like Cloudflare or Voxility, use RESTful APIs to allow customers and resellers access to their infrastructure information, DDoS stats, network performance, or dashboard controls. Access to such APIs is granted either by "API tokens", or customer status validations.

Public API implications

An important factor when an API becomes public is its "interface stability". Changes to the API—for example adding new parameters to a function call—could break compatibility with the clients that depend on that API.

When parts of a publicly presented API are subject to change and thus not stable, such parts of a particular API should be documented explicitly as "unstable". For example, in the Google Guava library, the parts that are considered unstable, and that might change soon, are marked with the Java annotation @Beta.

A public API can sometimes declare parts of itself as deprecated or rescinded. This usually means that part of the API should be considered a candidate for being removed, or modified in a backward incompatible way. Therefore, these changes allow developers to transition away from parts of the API that will be removed or not supported in the future.

On February 19, 2020, Akamai published their annual "State of the Internet" report, showcasing the growing trend of cybercriminals targeting public API platforms at financial services worldwide. From December 2017 through November 2019, Akamai witnessed 85.42 billion credential violation attacks. About 20%, or 16.55 billion, were against hostnames defined as API endpoints. Of these, 473.5 million have targeted financial services sector organizations.

Documentation

API documentation describes the services an API offers and how to use those services, aiming to cover everything a client would need to know for practical purposes.

Documentation is crucial for the development and maintenance of applications using the API. API documentation is traditionally found in documentation files but can also be found in social media such as blogs, forums, and Q&A websites.

Traditional documentation files are often presented via a documentation system, such as Javadoc or Pydoc, that has a consistent appearance and structure. However, the types of content included in the documentation differ from API to API.

In the interest of clarity, API documentation may include a description of classes and methods in the API as well as "typical usage scenarios, code snippets, design rationales, performance discussions, and contracts", but implementation details of the API services themselves are usually omitted.

Reference documentation for a REST API can be generated automatically from an OpenAPI document, which is a machine-readable text file that uses a prescribed format and syntax defined in the OpenAPI Specification. The OpenAPI document defines basic information such as the API's name and description, as well as describing operations the API provides access to.

API documentation can be enriched with metadata information like Java annotations. This metadata can be used by the compiler, tools, and by the run-time environment to implement custom behaviors or custom handling.

Dispute over copyright protection for APIs

In 2010, Oracle Corporation sued Google for having distributed a new implementation of Java embedded in the Android operating system. Google had not acquired any permission to reproduce the Java API, although permission had been given to the similar OpenJDK project. Google had approached Oracle to negotiate a license for their API, but were turned down due to trust issues. Despite the disagreement, Google chose to use Oracle's code anyway. Judge William Alsup ruled in the Oracle v. Google case that APIs cannot be copyrighted in the U.S and that a victory for Oracle would have widely expanded copyright protection to a "functional set of symbols" and allowed the copyrighting of simple software commands:

To accept Oracle's claim would be to allow anyone to copyright one version of code to carry out a system of commands and thereby bar all others from writing its different versions to carry out all or part of the same commands.

Alsup's ruling was overturned in 2014 on appeal to the Court of Appeals for the Federal Circuit, though the question of whether such use of APIs constitutes fair use was left unresolved.

In 2016, following a two-week trial, a jury determined that Google's reimplementation of the Java API constituted fair use, but Oracle vowed to appeal the decision. Oracle won on its appeal, with the Court of Appeals for the Federal Circuit ruling that Google's use of the APIs did not qualify for fair use. In 2019, Google appealed to the Supreme Court of the United States over both the copyrightability and fair use rulings, and the Supreme Court granted review. Due to the COVID-19 pandemic, the oral hearings in the case were delayed until October 2020.

The case was decided by the Supreme Court in Google's favor with a ruling of 6–2. Justice Stephen Breyer delivered the opinion of the court and at one point mentioned that "The declaring code is, if copyrightable at all, further than are most computer programs from the core of copyright." This means the code used in APIs are more similar to dictionaries than novels in terms of copyright protection.

Inequality (mathematics)

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Inequality...