Marc Lowell Andreessen ( ann-DREE-sən; born July 9, 1971) is an American entrepreneur, venture capital investor, and software engineer. He is the co-author of Mosaic, the first widely used web browser with a graphical user interface; co-founder of Netscape; and co-founder and general partner of Silicon Valley venture capital firm Andreessen Horowitz. He co-founded and later sold the software company Opsware to Hewlett-Packard. Andreessen is also a co-founder of Ning, a company that provides a platform for social networking websites. He sits on the board of directors of Meta Platforms. Andreessen was one of six inductees in the World Wide Web Hall of Fame announced at the First International Conference on the World-Wide Web in 1994. As of February 2023, his net-worth is estimated at $1.7 billion by Forbes.