'So glad you exist': Elon Musk wishes Wikipedia on its 20th birthday

Wishing Wikipedia on its 20th anniversary on Friday, Tesla's billionaire CEO Elon Musk tweeted, "Happy birthday Wikipedia! So glad you exist." Founded on January 15, 2001, by American-British entrepreneur Jimmy Wales, Wikipedia is now the seventh-most popular website in the world. It hosts more than 55 million articles which attract 15 billion hits from visitors every month.