Marc Andreessen

Marc Andreessen is an American entrepreneur, investor, and software engineer known for helping to shape the modern internet and the technology startup ecosystem. Marc's estimated net worth is around $1.9 billion as of 2025. 

Andreessen co-founded Mosaic Communications, later renamed Netscape Communications, where he helped develop the Netscape Navigator browser. Netscape was sold to AOL in 1999 for $4.3 billion, and Andreessen became AOL’s Chief Technology Officer. That same year, he was named to the MIT Technology Review's TR100 list.

After Netscape, he co-founded Loudcloud, which was later renamed Opsware and sold to Hewlett-Packard for $1.6 billion in 2007. 

Marc co-founded the venture capital firm Andreessen Horowitz (a16z) with Ben Horowitz. The firm has invested in some of the world’s most successful technology companies including Facebook, Twitter, GitHub, Pinterest, Coinbase, and Skype. Marc also supported the development of special economic zones and modern cities focused on technology and innovation.

Marc has served on the boards of Meta (Facebook), eBay, Hewlett-Packard Enterprise, and others. He has advised tech leaders, including Mark Zuckerberg. He co-founded the social networking platform Ning and has written essays including the influential “Software is Eating the World”.

He was born on 9 July 1971 in Cedar Falls, Iowa, and was raised in Wisconsin. He earned a bachelor’s degree in computer science from the University of Illinois at Urbana-Champaign, where he co-created Mosaic, the first widely used web browser with a graphical interface. This innovation marked a major turning point in the development of the World Wide Web.

Marc Lowell Andreessen was born on 9 July 1971 in Cedar Falls, Iowa, United States. He was raised in New Lisbon, Wisconsin. His father, Lowell Andreessen, worked in the agricultural industry, and his mother, Patricia, was a homemaker. Marc developed an early interest in computers and programming.

In 1989, Marc enrolled at the University of Illinois at Urbana–Champaign (UIUC) to study computer science. During his time as a student, he completed internships at IBM in Austin, Texas, and worked at the National Center for Supercomputing Applications (NCSA). In 1993, while still an undergraduate, he co-created the Mosaic web browser with Eric Bina. Mosaic was the first widely used internet browser with a graphical user interface and played a key role in the expansion of the World Wide Web.

In 1994, Marc moved to California and co-founded Mosaic Communications Corporation with Jim Clark. The company was later renamed Netscape Communications Corporation. They released Netscape Navigator, one of the most popular web browsers at the time. In 1995, the company launched its initial public offering, and Marc gained widespread attention. In 1999, AOL acquired Netscape for $4.3 billion, and Marc became Chief Technology Officer at AOL.

Later in 1999, Marc co-founded Loudcloud with Ben Horowitz, Tim Howes, and In Sik Rhee. The company offered cloud infrastructure services. In 2003, it was renamed Opsware and shifted its focus to data centre automation software. Marc served as Chairman. In 2007, Hewlett-Packard acquired Opsware for $1.6 billion.

In 2004, Marc co-founded Ning, a platform that allowed users to create custom social networks. Ning was sold to Mode Media in 2011 for a reported $150 million, and Marc joined its board of directors.

In 2009, Marc co-founded the venture capital firm Andreessen Horowitz (a16z) with Ben Horowitz. The firm started with $300 million in capital and has grown to manage over $30 billion. It has invested in many well-known companies, including Facebook, Twitter, GitHub, Pinterest, Coinbase, Airbnb, Skype, Clubhouse, and Stripe. Marc became known for backing early-stage startups and shaping Silicon Valley’s venture capital model. In 2011, Marc and the firm’s partners pledged to donate half their lifetime venture capital income to charitable causes.

Marc has served on the boards of several major companies, including Meta (Facebook), eBay, Hewlett Packard Enterprise, Oculus VR, OpenGov, Dialpad, TinyCo, Anki, and Stanford Hospital. He has also supported the development of new economic and urban models through investment in special economic zones such as California Forever in the United States, Próspera in Honduras, and Praxis, a planned innovation community. These efforts are backed by Pronomos Capital, which funds experimental charter cities and technology-based developments.

In 2012, Marc published the essay "Software is Eating the World", explaining how software was transforming global industries. In 2013, he was one of five pioneers awarded the Queen Elizabeth Prize for Engineering for contributions to internet technologies. He has also supported innovation in cryptocurrency and decentralised finance and has served as an advisor on the Neom project in Saudi Arabia.

In 2020, Marc published another influential essay titled "It's Time to Build", which called for more investment in infrastructure and technology, especially in response to challenges seen during the COVID-19 pandemic. In 2023, he released the "Techno-Optimist Manifesto", a statement encouraging belief in progress through technology.

Marc remains active in technology, venture capital, and public policy discussions. He appears regularly in podcasts produced by Andreessen Horowitz, often with Ben Horowitz and industry leaders. Topics include artificial intelligence, the future of technology, crypto, startup funding, and regulation. Some of the companies he currently supports through a16z include Applied Intuition, Carta, Coinbase, Dialpad, Flow, Golden, Honor, OpenGov, Samsara, Simple Things, and TipTop Labs.

Marc has also been involved in publishing content on AI policy in collaboration with Microsoft. He continues to advise founders and companies and remains a key voice in the technology investment space.

As of 2025, Marc Andreessen’s estimated net worth is $1.9 billion. He lives with his wife, Laura Arrillaga, in California. She is the founder of the Silicon Valley Social Venture Fund and daughter of real estate investor John Arrillaga. They have one son. Marc Andreessen continues to be a leading figure in technology, innovation, and venture capital.

Marc Andreessen is known for his visionary ideas and insights, which have played a significant role in shaping the tech industry. Throughout his career, he has championed a number of important initiatives, including the development of the internet, the rise of social media, and the emergence of cryptocurrencies.

One of Andreessen's key visions is the power of software to transform the world. He believes that software is the key driver of innovation and that it has the potential to revolutionize every aspect of our lives. He has been instrumental in developing key software technologies such as web browsers, which have opened up new possibilities for communication and commerce.

Another key vision of Andreessen is the importance of entrepreneurship and innovation. He has been a strong advocate for the role of startups in driving economic growth and creating new opportunities. He has encouraged entrepreneurs to take risks and pursue bold ideas, and has invested in numerous startups that have gone on to achieve great success.

Marc Andreessen has received several honours for his work in technology. In 1994, he was inducted into the World Wide Web Hall of Fame. In 1999, he was named one of the top 100 innovators under 35 by MIT Technology Review. In 2012, he was listed in Time 100 as one of the most influential people in the world. In 2013, he received the Queen Elizabeth Prize for Engineering for his role in the development of the internet. His essay "Software is Eating the World" has also been widely cited and respected in the tech industry.