Wikipedia (WIK-i-PEE-dee-ə) is a collaboratively edited, multilingual, free Internet encyclopedia supported by the non-profit Wikimedia Foundation. Wikipedia's 30 million articles in 287 languages, including over 4.3 million in the English Wikipedia, are written collaboratively by volunteers around the world. Almost all of its articles can be edited by anyone having access to the site.[4] It is the largest and most popular general reference work on the Internet,[5][6][7][8][9] ranking sixth globally among all websites on Alexa, and having an estimated 365 million readers worldwide.[5][10]