Wikipedia

Wikipedia was a website-based database of knowledge created in the 21st century. Rhys Williams used Wikipedia to investigate the Ghost Train. (AUDIO: Ghost Train)

When the Seventh Doctor changed history slightly, he mentioned that he would need to edit Wikipedia to reflect the change. (AUDIO: Mask of Tragedy)

Amble the Fairly Ugly Doll had a Wikipedia page which was often hacked and altered. (PROSE: Writer's Notes)

Alice Obiefune once remarked that Wikipedia was "decidedly light" on the part of history where the United States Conference were attacked by werewolves. (COMIC: The Long Con)

When the year 2004 was erased in 2019, Wikipedia had no record of that year. (PROSE: Time Lapse)

Later, Space Wikipedia documented the history of planets such as Kepzyr. (PROSE: Frank Reade, Jr.'s Electric Time Canoe)

Behind the scenes
Though unremarked in any of these stories, Wikipedia is a non-profit wiki, founded by Jimmy Wales and Larry Sanger. Wales also co-founded the for-profit company Wikia, which hosts, as a subdomain, the Tardis Data Core, this site.