Quick Answer: Wikipedia is a free online encyclopedia written and maintained by a community of volunteers, known as Wikipedians, through open collaboration and the wiki software MediaWiki. Founded by Jimmy Wales and Larry Sanger in 2001, Wikipedia has been hosted since 2003 by the Wikimedia Foundation, an American nonprofit organization funded mainly by donations from readers. Wikipedia is the largest and most-read reference work in history. Initially available only in English, Wikipedia exists in over 340 languages and is one of the world's most visited websites. The English Wikipedia, with over 7 million articles, remains the largest of the editions, which together comprise more than 66 million articles and attract more than 1.5 billion unique device visits and 13 million edits per month as of April 2024. As of December 2025, over 25% of Wikipedia's traffic comes from the United States, while Japan accounts for nearly 7%, and the United Kingdom, Germany, and Russia each represent around 5%.