Marc Lowell Andreessen (/ænˈdriːsən/ ann-DREE-sən; born July 9, 1971) 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;^[3] and co-founder and general partner of Silicon Valley venture capital firm Andreessen Horowitz. He 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 Facebook, eBay, and Hewlett Packard Enterprise,^[4] among others. 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.^[5].

Andreessen was born in Cedar Falls, Iowa, and raised in New Lisbon, Wisconsin.^[6] He is the son of Patricia and Lowell Andreessen, who worked for a seed company.^[7] In December 1993,^[6] he received his bachelor's degree in computer science from the University of Illinois at Urbana–Champaign.^[8] As an undergraduate, he interned twice at IBM in Austin, Texas.^[9] He worked in the AIX graphics software development group which was responsible for the MIT X-windows implementation and ports of the 3D language API's: SGI's Graphics Language (GL) and PHIGS. He also worked at the National Center for Supercomputing Applications (NCSA) at the University of Illinois, where he became familiar with Tim Berners-Lee's open standards for the World Wide Web. Andreessen and full-time salaried co-worker Eric Bina worked on creating a user-friendly browser with integrated graphics that would work on a wide range of computers. The resulting code was the Mosaic Web browser.

After his graduation from UIUC in 1993, Andreessen moved to California to work at Enterprise Integration Technologies. Andreessen then met with Jim Clark, the founder of Silicon Graphics, who had recently exited the firm. Clark believed the Mosaic browser had great commercial possibilities and suggested starting an Internet software company. Soon, Mosaic Communications Corporation was in business in Mountain View, California, with Andreessen as co-founder and vice president of technology. The University of Illinois was unhappy with the company's use of the Mosaic name, so Mosaic Communications changed its name to Netscape Communications, and its flagship Web browser was the Netscape Navigator.^[11]

Netscape's IPO in 1995 put Andreessen into the public eye. He was featured on the cover of Time^[12][13] and other publications.^[14]

Netscape was acquired in 1999 for $4.3 billion by AOL. Andreessen's hiring as its Chief Technology Officer was contingent on the completion of the acquisition.^[15] The same year, he was named to the MIT Technology Review TR100 as one of the top 100 innovators in the world under the age of 35.^[16]

After AOL acquired Netscape in late 1998, Andreessen went on to found Opsware with Ben Horowitz, Tim Howes, and In Sik Rhee,^[17] originally named Loudcloud, a company providing computing, hosting and software services to consumer facing internet and e-commerce companies. Loudcloud sold its hosting business to EDS and changed its name to Opsware in 2003, with Andreessen serving as chairman. Acquired by Hewlett-Packard for $1.6 billion in 2007, it was one of the first companies to offer software as a service and to attempt cloud hosting.^[18]

Between 2005 and 2009, Andreessen and longtime business partner Ben Horowitz separately invested a total of $4 million in 45 start-ups that included Twitter and Qik.^[19] The two became well known as super angel investors.^[19] On July 6, 2009, Andreessen and Horowitz announced their Silicon Valley venture-capital firm Andreessen Horowitz.^[20]

The firm had been scrutinized among several other venture capital firms for lack of diversity in its workforce.^[21] The Information's Future List 2015 & 2016 ranked Andreessen Horowitz 55th and 47th, respectively, based on their ethnic and gender diversity as well as the age of people on their investment teams. According to the data, the firm's senior investment team was 94% male in 2015,^[22] scoring 0.0 for gender diversity in 2016 and April 2018.^[23][24]

In an interview with New York Magazine, Andreessen stated the diversity discussion was valid, however, he believed the firm, as well as other venture capital firms of Silicon Valley, had been wrongly accused of intentionally discriminating against women and people of color.^[25] When asked specifically about the critique of ethnic and gender diversity in Silicon Valley, Andreessen responded that the issues were the "same thing."^[26]

Begun with an initial capitalization of $300 million,^[27] within three years the firm grew to $2.7 billion under management across three funds.^[28] Andreessen Horowitz's portfolio holdings include Facebook, Foursquare, GitHub, Pinterest, Twitter, and Honor, Inc.^[29]

On September 1, 2009, an investor group that included Andreessen Horowitz acquired a majority stake in Skype for $2.75 billion,^[30] which was considered risky.^[31] The deal paid off in May 2011 when Microsoft bought Skype for $8.5 billion.^[31] Additionally, Andreessen and Horowitz made personal investments in headset maker Jawbone in 2006. In 2010, the firm assisted Silicon Valley attorney Ted Wang in creating the first free standardized seed round financing documents, the Series Seed Documents.^[32] The firm announced a $49 million investment in Jawbone in March 2011.^[33] In February 2011, Andreessen Horowitz's $80 million investment in Twitter made it the first venture firm to hold stock in all four of the highest-valued, privately held social media companies (at that time): Facebook, Groupon, Twitter, and Zynga.^[34]

Andreessen first joined eBay board of directors in 2008, and served on the board for six years.^[35] In October 2014, Andreessen announced his resignation from the board due to the company's decision to break off its online payments unit PayPal. The decision to cut ties with PayPal was a point of contention between Andreessen and investor Carl Icahn. Icahn advocated for the PayPal split while Andreessen opposed the spin off, resulting in public disputes. Andreessen was accused by Icahn of putting his own interests in front of what was best for shareholders. Icahn published his argument in an open letter that detailed alleged conflicts of interest in eBay's 2009 sale of Skype to a group of private investors, which included Andreessen's own firm.^[36][37]

Andreessen advises the leaders of companies in which Andreessen Horowitz invests, including Mark Zuckerberg of Facebook and Mark Pincus of Zynga.^[38]

Andreessen and Horowitz were ranked no. six on Vanity Fair's 2011 New Establishment List,^[39] no. 1 on CNET's 2011 most influential investors list^[40] and no. 2 and 21, respectively, on the 2012 Forbes Midas List of Tech's Top Investors.^[41]

In April 2012, Andreessen and Andreessen Horowitz General Partners Ben Horowitz, Peter Levine, Jeff Jordan, John O'Farrell, and Scott Weiss pledged to donate half of their lifetime incomes from venture capital to charitable organizations.^[42]

In 2012, Andreessen was named in the Time 100, an annual list of the 100 most influential people in the world assembled by Time.^[43]

In 2013, Andreessen was one of five Internet and Web pioneers awarded the inaugural Queen Elizabeth Prize for Engineering.^[44]

Andreessen cofounded and was chairman of Ning, the third company he established after Netscape and Loudcloud.^[45] In September 2011, it was announced that Ning had been sold to Mode Media for a reported price of $150 million. Andreessen joined Glam Media's board of directors following the sale.^[46]

He is a personal investor in companies including LinkedIn^[47] and boutique bank Raine.^[48]

Andreessen serves on the board of Facebook,^[3] eBay, Hewlett Packard Enterprise, Kno,^[49] Stanford Hospital,^[50] Bump Technologies, Anki,^[51] Oculus VR,^[52] Dialpad, and TinyCo.^[53]

Hewlett Packard Enterprise announced in February 2018 that board member Andreessen would not seek reelection at the 2018 Annual Meeting of Stockholders on April 4.^[54] In his time at Hewlett Packard, Andreessen had been partially blamed for some of the company's failures, including the recruiting of Leo Apotheker as well as the acquisitions of Autonomy and Palm.^[55][56]

He serves as advisor to Asana and director of CollabNet.^[57]

Andreessen is a proponent of Bitcoin and cryptocurrency.^[58]

Andreessen serves on an advisory board for Neom, the Saudi Arabia’s plan to build a futuristic "mega city" in the desert.^[59][60]

Andreessen married Laura Arrillaga in 2006.^[61] She is the founder of the Silicon Valley Social Venture Fund and daughter of Silicon Valley real estate billionaire John Arrillaga. They have one son together.

In 2012, Andreessen expressed some support for Republican candidate Mitt Romney.^[62] During the 2016 primary season, he endorsed Republican candidate Carly Fiorina, but after Fiorina dropped out of the race, Andreessen switched his endorsement to the Democratic nominee Hillary Clinton, citing the Republican nominee Donald Trump's anti-immigration stance.^[63][64]

In February 2016, Marc Andreessen posted a tweet in response to India's decision to apply net neutrality to Facebook's proposed project Free Basics. The tweet suggested that anti-colonialism had been catastrophic for the Indian people. Andreessen later deleted the tweet following criticism from Indians and non-Indians alike (including Facebook founder Mark Zuckerberg).^[65][66][67] Facebook spent millions advertising Free Basics to the Indian public.^[68] The project failed due to violations, setting preferential tariffs in accessing content and setting up a "walled garden" on the internet.^[69][70]

Andreessen was a supporter for the controversial British journalist Milo Yiannopoulos, whose verified status was revoked by Twitter in 2016 for abusive behavior and hateful conduct, growing into an ongoing controversy. Marc Andreessen tweeted in support of Yiannopoulos.^[71]

In April 2016, Facebook shareholders filed a class action lawsuit to block Zuckerberg's plan to create a new class of non-voting shares. The lawsuit alleges Andreessen secretly coached Zuckerberg through a process to win board approval for the stock change, while Andreessen served as an independent board member representing stockholders.^[72]

According to court documents, Andreessen shared information with Zuckerberg regarding their progress and concerns as well as helping Zuckerberg negotiate against shareholders. Court documents included transcripts of private texts between Zuckerberg and Andreessen.^[73]