Best of the Web

The Pioneer

Marc Andreessen
ning.com

Andreessen revolutionized Internet navigation and helped fuel the dot-com boom. He co-created the first widely used Web browser, Mosaic, and with Jim Clark co-founded Netscape Communications, which later went public and was bought by AOL. Andreessen, who majored in computer science at the University of Illinois, went on to create Opsware, a maker of software that helps companies manage data centers, before selling it to Hewlett-Packard. Now, he's hard at work at Ning, a startup that helps users build their own social networks.