Encyclopædia Dramatica (often abbreviated ED and æ) is a satirical open wiki that uses MediaWiki software. Launched on December 10, 2004, it lampoons both encyclopedic topics and current events, especially those related or relevant to contemporary Internet culture. It is frequently utilized by a socially fluid and dynamic Internet subculture known as Anonymous. The not safe for work site celebrates a subversive "trolling culture", and documents Internet memes, culture, and events, such as mass organized pranks, trolling events, "raids", large scale failures of Internet security, and criticism of Internet communities which are accused of self-censorship in order to garner prestige or positive coverage from traditional and established media outlets.
Journalist Julian Dibbell described Encyclopædia Dramatica as the site "where the vast parallel universe of Anonymous in-jokes, catchphrases, and obsessions is lovingly annotated, and you will discover an elaborate trolling culture: Flamingly racist and misogynist content lurks throughout, all of it calculated to offend." Ninemsn described Encyclopædia Dramatica as: "Wikipedia's evil twin. It’s a site where almost every article is biased, offensive, unsourced, and without the faintest trace of political correctness. A search through its archives will reveal animated images of people committing suicide, articles glorifying extreme racism and sexism, and a seemingly endless supply of twisted, shocking views on just about every major human tragedy in history."
On April 14, 2011, the original URL of the site was redirected to a new website named Oh Internet that bore little resemblance to Encyclopedia Dramatica. Parts of the ED community harshly criticized the changes. On the night of the Encyclopedia Dramatica shutdown, regular ED visitors bombarded the 'Oh Internet' Facebook wall with hate messages. The Web Ecology Project made a downloadable archive of former Encyclopedia Dramatica content. Fan-made torrents and several mirrors of the original site were subsequently generated, before the wiki located at encyclopediadramatica.se (formerly encyclopediadramatica.ch) emerged as the only one still active.