Baidu, Inc. is a Chinese web services company headquartered in the Baidu Campus in Haidian District, Beijing. Baidu offers many services, including a Chinese language search engine for websites, audio files, and images. Baidu offers 57 search and community services including Baidu Baike, an online collaboratively built encyclopedia, and a searchable keyword-based discussion forum. Baidu was established in 2000 by Robin Li and Eric Xu. Both of the co-founders are Chinese nationals who studied and worked overseas before returning to China. In October 2012, Baidu ranked 5th overall in the Alexa Internet rankings. Baidu provides an index of over 740 million web pages, 80 million images, and 10 million multimedia files. Baidu offers multimedia content including MP3 music and movies.