Marc Andreessen is an American entrepreneur, investor, and software engineer. He is the co-author of Mosaic, the first widely used Web browser; co-founder of Netscape; and co-founder and general partner of a16z.
He founded and later sold the software company Opsware to Hewlett-Packard. Andreessen is also a co-founder of NingNing, a company that provides a platform for social networking websites. He sits on the board of directors of FacebookFacebook, eBayeBay, and Hewlett Packard Enterprise, among others. A frequent keynote speaker and guest at Silicon Valley conferences, Andreessen was one of only six inductees in the World Wide Web Hall of Fame announced at the First International Conference on the World-Wide Web in 1994.