Marc Andreessen

Marc Lowell Andreessen (/ænˈdriːsən/ an-DREE-sən; born July 9, 1971) is an American businessman, venture capitalist, and former software engineer. He is the co-author of Mosaic, the first web browser to display inline images; 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; he also co-founded Ning, a company that provides a platform for social networking websites. In 2024, he became an advisor to Donald Trump.[2] As of June 2026, Forbes estimated Andreessen's net worth at $1.9 billion. Andreessen was born in Cedar Falls, Iowa, and raised in New Lisbon, Wisconsin,[3] which he considered "the sticks".[4] He is the son of Patricia, customer service operator at Lands' End, and Lowell Andreessen, who worked as a sales manager for the seed producer Pioneer Hi-Bred International.[4][1][5] He has a younger brother named Jeff. Andreessen has stated that he had problematic relationships with his parents and brother, and that he did not like to talk about them.[4][6] Andreessen discovered programming at age 12.[4] In December 1993,[3] Andreessen received his bachelor's degree in computer science from the University of Illinois at Urbana–Champaign (UIUC).[7] As an undergraduate, he interned twice at IBM in Austin, Texas.[8] He worked in the AIX graphics software development group responsible for the MIT X implementation and ports of the 3D language APIs: SGI's Graphics Language (GL) and PHIGS.[citation needed] He also worked as a programmer, earning $6.85 per hour (equivalent of $15.49/hr in 2026), at the National Center for Supercomputing Applications (NCSA) at the University of Illinois. At that time, he became familiar with Tim Berners-Lee's open standards for the World Wide Web, but the World Wide Web browser required advanced programming skills to use.