Entrepreneur Elon Musk on Saturday wished a "Happy Birthday" to the online information service, Wikipedia, which yesterday celebrated its 20th foundation day. "So Glad You Exist," he tweeted.

Wikipedia, started by Jimmy Wales and Larry Sanger in 2001, is one of the most popular websites on the Internet. The ad-free website hosts millions of articles on people, organisations, places etc. It is a go-to website for those seeking information on almost any topic.

Anyone can create or edit a topic on the website. Lakhs of volunteers across the globe work, without pay, to keep Wikipedia pages updated and largely accurate. It is run by non-profit Wikimedia foundation.

Mr Musk, the entrepreneur behind the electric cars company, Tesla, and the private space company, SpaceX, earlier this month became the richest person in the world. His net worth was 188.5 billion dollars, more than Jeff Bezos', who owns Amazon.

According to the blog in the Tesla fan site Tesmanian, Tesla is in talks with five Indian states to open stores, an office, an R&D centre and a factory for production.

Earlier this month, Elon Musk confirmed his India plans for Tesla centres with a two-word tweet. "As promised," he wrote.