After barely a month at Commerce One, Jones is having second thoughts about agreeing to let a writer shadow him for a day. "If you mention that I hurt my knee playing tennis, say that I won," he says. Jones, who is 6 feet tall, wears bifocals and has straight gray hair that he neatly combs back over the top of his head. His fair skin sometimes turns red when he laughs. He spends the day limping between his desk and conference table, meeting with scheduled visitors and talking on the telephone. He checks e-mail constantly; on the road, he uses a wireless BlackBerry instead of a laptop and cell phone; and he's such an e-mail enthusiast that he got his dog an address. The only decorating he's done in his office was hooking up a television set tuned to MSNBC.

Outside, the foothills of Mount Diablo are turning brown from the dry heat of May, and Jones is starting to realize what it means to live in the San Francisco Bay area: The rolling blackouts have begun. He asks a public relations person how to find out if his power will be shut off. His standard joke is that he'll buy a house once he figures out where the best power grids are. "I may end up living next door to a fire station," he quips.

For now, however, he splits his time between a temporary residence in Pleasanton, 40 miles southeast of the city, and his pillared brick mansion in Memphis. When his daughter goes away to North Carolina State in the fall, both Jones and his wife will spend more time in California. Jones says they'll keep their Memphis address to make the transition easier for their daughter and also because his parents and in-laws live in Memphis. But the fact is that the Mississippi River town of 650,000 is the only home either of them have known.

Jones was born there in 1952, the second of two sons. His father was a banker who brought home investment reports that inspired the 12-year-old Jones to buy stocks with his lawn-mowing money. By age 14, he was reading The Wall Street Journal every day. During his freshman year at the University of Memphis, where he earned a bachelor's degree in accountancy, he met his future wife, Debbie, then a sophomore in high school. They married four years later, in 1974, the same year Jones received a master's degree in accounting and finance from Memphis State University. The next year he started at FedEx, then a 2-year-old company with only 2,000 employees.

Jones, a CPA, held various finance jobs with FedEx before coming to IT in a roundabout way. In 1983, the company started a proprietary network for plain-paper fax machines, and Jones was lead finance person for the project. When it was shut down in 1986, he became vice president of customer automation and invoicing in the sales department, where he got increasingly involved with technology; so much so that five years later, when the CIO left, CEO Fred Smith offered Jones the job.

As CIO, he earned a reputation as a visionary: a bureaucracy-buster who could make things happen even if it didn't make everyone happy. "He's not a guy who lets water flow naturally; he wants to change the course of the stream," says Richard Poff, managing director for supply chain developments at FedEx. Jones recognized early on how the Internet would revolutionize the way businesses interact with customers. In 1994, he led a push to introduce package tracking on FedEx's website, arguably making FedEx the first major corporation to do business over the Web. The company was featured in this magazine's CIO-100 Best Practices issue. In 1996, Jones spearheaded a technology initiative that made FedEx the first company to process shipping transactions over the Internet. By 2000, the IT organization was his empire, with 5,000 employees worldwide and a budget approaching US$2 billion. CEO Smith liked to say that Jones was not CIO but the CEO of IT. Jones's total compensation in 2000 topped $2.5 million, which according to Computerworld made him the third most highly paid CIO in the country.

But he was restless. Two years ago, he and his wife were driving home from a Memphis State football game in Nashville when he mentioned possibly changing jobs. "I almost drove off the road," Debbie Jones recalls. When Jones became eligible for a pension, after 25 years with the company, he announced his retirement. During his twilight there, in August 2000, FedEx named the centerpiece building of its new 1-million-square-foot IT campus after him.

Jones is careful to say that he was still having fun at FedEx, but the company simply wasn't moving fast enough for him. "The high growth rates that I had seen in previous years that really drive a lot of change and create a different level of intensity; that creates a whole different pace, and that's really what I had enjoyed most," he says. He also felt like he'd spent long enough in the CIO role, which he compares to fitting an SUV into a parking space for a compact car: "You don't have a lot of flexibility, and you get in some very tight spots," he says.

A friend indicates that Jones's entrepreneurial bent was getting stifled. "Different initiatives came up at FedEx, and he decided it was an opportune time to jump out and do the next thing on his list," says Jeffrey Webber, a consultant who has served on several boards of directors with Jones in the past decade. "There were certain things he wanted to do that would have been easier to do in a small company," says Webber, a partner at the Palo Alto, Calif.-based R.B. Webber and Co., and also a member of Commerce One's board of directors.

When Jones retired from Federal Express, "I think people were surprised," says his successor, Rob Carter, then CTO. "But based on his level of energy and age, there was confidence that he would go do more interesting stuff. You have to understand our culture. We don't think of [retirement] quite the same way as the world thinks of it—you know, OK, I'm hanging up my cleats."

Hardly. In September 2000, on the Monday after his last Friday at FedEx, Jones started as CEO of Accel-KKR, a privately held Menlo Park, Calif.-based venture capital firm focused on the integration of online and offline assets. He took the job despite a $48,528 monthly consulting agreement with FedEx through the end of 2002, plus FedEx stock options that he could borrow money against and more stock options from three Internet companies where he is on the board of directors. (He says the FedEx consulting agreement was set up partially because he won't start receiving his annual pension of $588,000 until he turns 55.) In a press release, Accel-KKR Director James Breyer raved about Jones's appointment. But three months later Jones abruptly left, this time with no fanfare. After multiple requests for an interview, Breyer responded with a curt e-mail: "He left on very good terms."

Jones insists he just needed time off, but friends speculate that he left because of the market downswing in late 2000. When Jones took the job at Accel-KKR, "I think he was probably caught up in some of the dotcom euphoria," says Ralph Szygenda, CIO of General Motors, who has known Jones for several years and is a Commerce One customer.

Jones and his cocker spaniel, Freckles, spent the next three months poolside or watching TV. They both gained weight, which Jones is still trying to lose. "After about six weeks, I hit the wall. It was like, 'OK, I've seen all the Jerry Springer shows I want to see,'" Jones says.

Meanwhile, word that Jones had left Accel-KKR had reached Commerce One, where Chairman and CEO Mark Hoffman had conducted two failed searches for a COO to manage engineering, marketing, financial, legal and administrative operations. Hoffman, 54, had known Jones since the early 1990s, when Hoffman was CEO of Sybase, a relational database company that sold its wares to FedEx. "Dennis is not just a nice guy," Hoffman says. "He's a very focused, tough guy, and he can be very demanding but not in an abrasive, disruptive way."

During his son's soccer game in Arizona, Hoffman called Jones to gauge his interest. "I said, 'You need a big platform just like you had at FedEx, where you can grow this thing into a big, industry-changing event. I believe at Commerce One you have that opportunity.' I think he liked that, and I think that's why he fits in here so well." Jones heard the soccer crowd cheer in the background. A few weeks later, the deal was done.