Marc Andreessen
Co-founder, a16z
Biography
Marc Lowell Andreessen 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. As of June 2026, Forbes estimated Andreessen's net worth at $1.9 billion.
Career Timeline
Marc Lowell Andreessen (/ænˈdriːsən/ an-DREE-sən; born July 9, 1971) is an American businessman, venture capitalist, and former software engineer.
In December 1993, Andreessen received his bachelor's degree in computer science from the University of Illinois at Urbana–Champaign (UIUC).
The NCSA though refused to give the Mosaic team credit for their contribution, so Andreessen, disillusioned, decided to leave the center in 1994.
— Bob Metcalfe, InfoWorld, August 21, 1995, Vol.
In 1998, Bloomberg reported that Jeff was a history major at the University of Wisconsin.
Netscape was acquired in 1999 for $4.3 billion by AOL.
Between 2005 and 2009, Andreessen and Horowitz separately invested a total of $80 million in 45 startups, including Twitter and Qik.
Andreessen married Laura Arrillaga in 2006.
Notable Quotes
"[Netscape will soon reduce Windows to] a poorly debugged set of device drivers."
"1995 remark quoted in Ian Murdock, "Windows as a poorly debugged set of device drivers?", Ian Murdock's Weblog (2006-08-02); Andreessen in 2012 attributed the original quote to Bob Metcalfe, describing it as a "retweet"."
"Why Software Is Eating The World in The Wall Street Journal by Marc Andreessen on August 20, 2011"