Marc Andreessen (born July 9, 1971, in Cedar Falls, Iowa and raised in New Lisbon, Wisconsin, United States) is known as a entrepreneur, investor, startup coach, blogger, 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 co-founder of Ning, a company which provides a platform for social-networking websites. As of June 30, 2008, he is said to be joining the Board of Directors of Facebook. Andreessen is a frequent keynote speaker and guest at Silicon Valley conferences.

Source: Wikipedia