This piece originally appeared in Reuters Magazine.

As the embodiment of all that is great and good about Silicon Valley, Marc Andreessen is surprisingly unassuming. He is the earnest, clean-cut Midwestern boy made good, the state school grad who built a better mousetrap—the Web browser—and saw the world beat a path to his door. If being on the cover of Time magazine at age 24 ever went to his head, he didn’t show it. Andreessen simply did what great entrepreneurs are supposed to do: start new companies, again and again. His subsequent ventures never achieved the notoriety of his first, Netscape Communications, but they put to rest any suspicions that his early triumph was a fluke.

Over the years, Andreessen has earned great respect around Silicon Valley as a true visionary who understands where the technology world is going. He sits on the board of leading companies such as Facebook, Hewlett-Packard, and eBay, and serves as a mentor to up-and-coming entrepreneurs, notably Facebook CEO Mark Zuckerberg. And he’s a nice guy to boot, unpretentious and always excited to engage intellectually on technology, finance, company creation, and just about any other topic. What Andreessen has not done, though, is the one thing required for admission to the top tier of the Silicon Valley pantheon: build and lead a great company that defines the technology landscape for generations. Think of Apple, Hewlett-Packard, Intel, or Microsoft, and you will also conjure up the names that head any list of great technology industry leaders: Steve Jobs, Bill Hewlett, David Packard, Bob Noyce, Andy Grove, Gordon Moore, and Bill Gates.

Andreessen’s response to such observations is that he has no desire to run a big company. “I’m not psychologically wired for it,” he says. “All the people and process aspects of it, I can force myself to do but I don’t really like. When I was in management I never really loved it. I found it very stressful.” But even though he might sometimes claim to like nothing better than curling upwith a good book, Andreessen still has big goals. One might even say he is out to show that the very particular type of  Silicon Valley role-player that he embodies—the entrepreneurial technologist whose strength is vision rather than management—can be just as influential as the Fortune 500 CEO.

The vehicle of his ambitions is a venture capital firm, Andreessen Horowitz, which he launched in 2009 with his longtime collaborator, Ben Horowitz. In less than three years, Andreessen Horowitz has shaken up the venture world by raising $2.7 billion and adopting an unconventional approach that includes big, expensive bets on relatively mature companies like Facebook and Twitter, along with a startling volume and variety of smaller deals. Venture investors play a singular role in the unique business culture of Silicon Valley, and the great ones are powerful and revered figures in their own right. But Andreessen Horowitz aspires to create a new type of venture firm, one that puts the technical founder in the driver’s seat and provides a host of services beyond mere dollars.

As with any startup, success is hardly assured. It’s rare that new firms break into the top tier of venture capital, and rivals grumble that Andreessen Horowitz is moving recklessly fast and will never be able to generate the fat investment returns that the blue-chip venture firms often achieve. The specter of the great dot-com bust of 2000 also looms large. For now, though, Andreessen is in his element, indulging his endless intellectual curiosity even as he orchestrates deals and proselytizes about how “software is eating the world.” With Horowitz, he has an intimate business partnership that, by all accounts, is exceptionally effective. He works near Stanford University, out of a gleaming office complex on Sand Hill Road that was built by his wife’s father, a prominent real estate developer. (His wife, Laura Arrillaga-Andreessen, teaches philanthropy at Stanford and is the founder of two nonprofits; the family foundation is just next door.)