The software that runs Wikipedia, and the computer hardware, server farms and other systems upon which Wikipedia relies. In January 2001, Wikipedia ran on UseModWiki, written in Perl by Clifford Adams. The server still runs on Linux, although the original text was stored in files rather than in a database. Articles were named with the CamelCase convention. In January 2002, "Phase II" of the wiki software powering Wikipedia was introduced, replacing the older UseModWiki. Written specifically for the project by Magnus Manske, it included a PHP wiki engine. In July 2002, a major rewrite of the software powering Wikipedia went live; dubbed "Phase III", it replaced the older "Phase II" version, and became MediaWiki. It was written by Lee Daniel Crocker in response to the increasing demands of the growing project. In October 2002, Derek Ramsey created a botan automated program called Rambotto add a large number of articles about United States towns; these articles were automatically generated from U.S. census data. He thus increased the number of Wikipedia articles by 33,832. This has been called "the most controversial move in Wikipedia history".Lih, p. 99. In January 2003, support for mathematical formulas in TeX was added. The code was contributed by Tomasz Wegrzanowski. On 9 June 2003, Wikipedia's ISBN interface was amended to make ISBNs in articles link to Special:Booksources, which fetches its contents from the user-editable page . Before this, ISBN link targets were coded into the software and new ones were suggested on the page. See the edit that changed this. After 6 December 2003, various system messages shown to Wikipedia users were no longer hard coded, allowing Wikipedia to modify certain parts of MediaWiki's interface, such as the message shown to blocked users. On 12 February 2004, server operations were moved from San Diego, California to Tampa, Florida. On 29 May 2004, all the various websites were updated to a new version of the MediaWiki software. On 30 May 2004, the first instances of "categorization" entries appeared. Category schemes, like Recent Changes and Edit This Page, had existed since the founding of Wikipedia. However, Sanger had viewed the schemes as lists, and even hand-entered articles, whereas the categorization effort centered on individual categorization entries in each article of the encyclopedia, as part of a larger automatic categorization of the articles of the encyclopedia."Wikipedia:Categorization", Wikipedia. Retrieved 30 January 2007. After 3 June 2004, administrators could edit the style of the interface by changing the CSS in the monobook stylesheet at MediaWiki:Monobook.css. Also on 30 May 2004, with MediaWiki 1.3, the Template namespace was created, allowing transclusion of standard texts."Wikipedia:Template namespace", Wikipedia. Retrieved 17 September 2007. On 7 June 2005 at 3:00 a.m. Eastern Standard Time, the bulk of the Wikimedia servers were moved to a new facility across the street. All Wikimedia projects were down during this time. In March 2013, the first phase of the Wikidata interwiki database became available across Wikipedia's language editions. In July 2013, the VisualEditor editing interface was inaugurated, allowing users to edit Wikipedia using a WYSIWYG text editor (similar to a word processor) instead of wiki markup. An editing interface optimised for mobile devices was also released.
The software that runs Wikipedia, and the computer hardware, server farms and other systems upon which Wikipedia relies. In January 2001, Wikipedia ran on UseModWiki, written in Perl by Clifford Adams. The server still runs on Linux, although the original text was stored in files rather than in a database. Articles were named with the CamelCase convention. In January 2002, "Phase II" of the wiki software powering Wikipedia was introduced, replacing the older UseModWiki. Written specifically for the project by Magnus Manske, it included a PHP wiki engine. In July 2002, a major rewrite of the software powering Wikipedia went live; dubbed "Phase III", it replaced the older "Phase II" version, and became MediaWiki. It was written by Lee Daniel Crocker in response to the increasing demands of the growing project. In October 2002, Derek Ramsey created a botan automated program called Rambotto add a large number of articles about United States towns; these articles were automatically generated from U.S. census data. He thus increased the number of Wikipedia articles by 33,832. This has been called "the most controversial move in Wikipedia history".Lih, p. 99. In January 2003, support for mathematical formulas in TeX was added. The code was contributed by Tomasz Wegrzanowski. On 9 June 2003, Wikipedia's ISBN interface was amended to make ISBNs in articles link to Special:Booksources, which fetches its contents from the user-editable page . Before this, ISBN link targets were coded into the software and new ones were suggested on the page. See the edit that changed this. After 6 December 2003, various system messages shown to Wikipedia users were no longer hard coded, allowing Wikipedia to modify certain parts of MediaWiki's interface, such as the message shown to blocked users. On 12 February 2004, server operations were moved from San Diego, California to Tampa, Florida. On 29 May 2004 all the various websites were updated to a new version of the MediaWiki software. On 30 May 2004, the first instances of "categorization" entries appeared. Category schemes, like Recent Changes and Edit This Page, had existed since the founding of Wikipedia. However, Sanger had viewed the schemes as lists, and even hand-entered articles, whereas the categorization effort centered on individual categorization entries in each article of the encyclopedia, as part of a larger automatic categorization of the articles of the encyclopedia."Wikipedia:Categorization", Wikipedia. Retrieved 30 January 2007. After 3 June 2004, administrators could edit the style of the interface by changing the CSS in the monobook stylesheet at MediaWiki:Monobook.css. Also on 30 May 2004, with MediaWiki 1.3, the Template namespace was created, allowing transclusion of standard texts."Wikipedia:Template namespace", Wikipedia. Retrieved 17 September 2007. On 7 June 2005 at 3:00 a.m. Eastern Standard Time, the bulk of the Wikimedia servers were moved to a new facility across the street. All Wikimedia projects were down during this time. In March 2013, the first phase of the Wikidata interwiki database became available across Wikipedia's language editions. In July 2013, the VisualEditor editing interface was inaugurated, allowing users to edit Wikipedia using a WYSIWYG text editor (similar to a word processor) instead of wiki markup. An editing interface optimised for mobile devices was also released.