Marc Andreessen (born July 9, 1971, in Cedar Falls, Iowa and raised in New Lisbon, Wisconsin, United States) is one of the most successful entrepreneurs (called a Silicon Valley "whiz kid" ), startup coach, blogger, investor, and a multi-millionaire software engineer best known as co-author of Mosaic, the first widely-used web browser, and co-founder of Netscape Communications Corporation. He was the chair of Opsware, a software company he founded originally as Loudcloud, when it was acquired by Hewlett-Packard. He is also a cofounder of Ning, a company which provides a platform for social-networking websites.
Andreessen received his Bachelor's degree in computer science from the University of Illinois at Urbana-Champaign. As an undergraduate, he interned one summer at IBM in Austin, Texas, United States. He also worked at the university's National Center for Supercomputing Applications (NCSA), where he became familiar with Tim Berners-Lee's open standards for the World Wide Web. Andreessen and a 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.
In the year between the formation of the company and its IPO, Andreessen engaged in extensive public outreach on behalf of his vision of the web browser's potential, something he had in fact done continuously since making the decision to distribute Mosaic for free via the Internet.
One of these events, hosted by Internet commercialization pioneer Ken McCarthy, was captured on video  and provides a unique look at the state of the web between the time Andreessen and his colleagues launched Mosaic and the time when web browsers and servers became mainstream commercial products. At the time of the recording, Andreessen was 23 years old.
Netscape's IPO in 1995 propelled Andreessen into the public's imagination. Featured on the cover of Time and other publications, Andreessen became the poster-boy wunderkind of the Internet bubble generation: young, twenty-something, high-tech, ambitious, and worth millions (or billions) of dollars practically overnight.
Netscape's success attracted the attention of Microsoft, which recognized the web's potential and wanted to put itself at the forefront of the rising Internet revolution. Microsoft licensed the Mosaic source code from Spyglass, Inc., an offshoot of the University of Illinois, and turned it into Internet Explorer. The resulting battle between the two companies became known as the Browser Wars.
Netscape was acquired in 1999 for $4.2 billion by AOL, which made Andreessen its Chief Technology Officer.
Historical Timeline for Marc Andreessen :