Silicon Valley is ruled by the tech world. It is the raison d’entre for much of the sustained prosperity that abounds in Northern California. As such, for our premiere San Francisco edition, it was a natural decision to highlight 25 of the most important and impressive Tech Titans-the men that have shaped the industry. And it just so happens that they all call Silicon Valley home.

Mark Zuckerberg
Company: Facebook
Home: Palo Alto
The Web 2.0 wunderkind designed the perfect vessel to make social networking appeal to the increasingly addicted masses; he actually made it useful for everyone, whether young or old, hip or geeky. At 24 years old, Zuckerberg represents tech’s next generation of connected users. It also helps that in 2007, Microsoft bought a stake in the company, valuing it at $15 billion, making Zuckerberg the youngest member of Forbes’ billionaires list, with a personal net worth around $1.5 billion.

John Morgridge
Company: Cisco
Home: Portola Valley
Cisco Systems was founded in 1984 in attempts to advance the development of IP-the basic language to communicate over the Internet and in private networks. Morgridge joined Cisco Systems, Inc. in 1988 as president and CEO, and grew the company from $5 million in sales to more than $1 billion, and from 34 employees to more than 2,250. In 1990 he took Cisco public, and in 1995 he was appointed chairman. During his tenure, Cisco has become the worldwide leader in networking for the Internet, with more than $25 billion in revenues and some 47,000 employees in 77 countries.

Charles Schwab
Company: Charles Schwab
Home: Atherton
When you think of revolutionaries in the world of personal finance, Schwab is the first name that comes to mind. The man who famously brought Wall Street back to Main Street by undercutting the big brokerage houses in the late 1970s was also one of the first to bring investing online (on CompuServe, well before the ’90s Internet trading frenzy). Today, Charles Schwab & Co. holds close to $1 trillion of client assets (the figure fluctuates as wildly as the market) and a $25 billion bank that stayed clear of the toxic debt that has choke-slammed so many other financial institutions, and Chuck himself is a multibillionaire.

Tom Perkins
Company: Kleiner Perkins Caufield & Byers
Home: Belvedere
One of Silicon Valley’s pioneers, Perkins’ venture capital firm, Kleiner Perkins Caufield & Byers, was an early backer of Genentech, Netscape, and Google. He is now, or has been, a director of the following firms: Acuson, Applied Materials, Compaq, Corning Works, Genentech, Hewlett Packard, Hybritech, LSI Logic, The News Corporation, Philips Electronics NV, Spectra-Physics, Symantec, and Tandem Computers. Not one to slow down, when he turned 70 several years ago, he decided to build the biggest, fastest, most technologically advanced, single-hulled sailing megayacht in the world, the 289-foot Maltese Falcon.

Gordon Moore
Company: Intel
Home: Woodside
In 1965, Moore predicted that the number of components the industry would be able to place on a computer chip would double every year. That phenomenon came to be known as Moore’s Law. Moore co-founded Intel in 1968, and in 1975, he updated his prediction to once every two years. It has become the guiding principle for the semiconductor industry to deliver ever-more-powerful chips while decreasing the cost of electronics. While the San Francisco native is retired from Intel, he is a director of Gilead Sciences Inc., a member of the National Academy of Engineering, and a fellow of the Royal Society of Engineers. Moore also serves on the board of trustees of the California Institute of Technology. He received the National Medal of Technology in 1990 and the Medal of Freedom, the nation’s highest civilian honor, from George W. Bush in 2002.