Entrepreneurs don't win against industry monopolies by competing on the incumbents' own terms. They win by changing the rules of the game.

Michael Robertson has followed that model with each of the three San Diego-based companies he has founded in the last six years. Each time, his ambitions have grown.

The Del Mar resident targeted the music industry in 1998 by founding the Internet music company MP3.com. He also put San Diego on the map as a region that could support a major Internet company, publicly rejecting advice that he move the company to the San Francisco Bay area.

After attracting fame (and notoriety from outraged music studios who accused him of encouraging piracy), Robertson sold MP3.com in 2001 to the French conglomerate Vivendi for more than $370 million.

Fourth time around

Robertson then went after software giant Microsoft by founding Lindows.com, maker of a Linux-based alternative to Microsoft's Windows operating system. The LindowsOS software, now in its fourth major revision, is sold separately and installed by the company on computers through the Web site of Wal-Mart and other retailers.

But so far, Lindows, of which Robertson is majority owner, hasn't made a serious dent in Microsoft's monopoly market share.

Now Robertson, 36, is taking on the telecommunications industry with his third venture, called SIPPhone Inc. The company makes telephones that communicate over the Internet with one another and regular phones that have toll-free numbers. There is no per-minute charge or monthly fee, even for international calls. They cost $129 per pair.

Making it simple

Like Robertson's other ventures, SIPPhone's business model is to take a new technology invented by geeks and make it usable by consumers.

Originality is not Robertson's claim to fame -- the technologies he has built those three companies around have been around for years. What makes him stand out is a commitment to selling these technologies to consumers.

Robertson understands what most technologists don't: They're incomprehensible to the average person. Techies often disdain to translate their maddeningly obscure number and acronym-prone argot into English. But Robertson is fixated on ease of use.

With MP3.com, Robertson centralized collection of Internet music in one place, making it easy to download. With LindowsOS, Robertson added a graphical interface to Linux, obscuring its complexity. He also added a Web-based software "library" called the Click-N-Run Warehouse that automates installing software.

A touch of Barnum

To reach consumers, Robertson also likes to play the showman. He promotes his ideas not only to the press, but in a weekly e-mail newsletter people can sign up for. New products and ideas are also important.

For example, Lindows.com recently announced that it would sell a complete computer, including a flat-panel LCD monitor, for just $449. And earlier this year, Lindows offered a version of the LindowsOS that runs from a CD-ROM, so people can test the software on their computers without installing anything or changing their computer settings.

Now with SIPPhone, Robertson is trying to marry the power of the Internet with the ease of use of traditional phones.

The talking Internet

Technology watchers have long predicted that the Internet would eventually take over routing telephone calls, which now mostly travel from line to line over circuits. Internet calling is more efficient and thus less expensive than these traditional circuit-based calls.

Internet voice quality used to be poor, but has now improved to be comparable or superior to that of cell phones. Behind the scenes, telecom companies are switching to the technology, and consumers and businesses are getting into the act. Still, most of the Internet phone services require the use of a computer, software and headsets, which must be configured to work.

By contrast, the SIPPhones are sold pre-configured to work immediately after being plugged into a broadband cable modem or DSL Ethernet socket. No computer is needed. No telephone company is needed. The phone rings, and you get an automated call announcing that the SIPPhone is working.

The profit search

As he did with Lindows, Robertson hopes to make money by getting his products into the hands of millions of consumers, then selling them on extra services. For Lindows, it's extra software programs and the Click-N-Run Warehouse.

For SIPPhone, Robertson admits that he doesn't know where the profit will come from, but that is not what he is worried about right now.

"Our number one goal with SIP is to get a million people out there using SIP and making SIP calls, because that's when the revenue possibilities really come to light," Robertson said.

If SIPPhone and other examples of Internet telephone service take off, telecom giants such as AT&T and SBC could lose millions as users abandon high-margin calls and services in favor of an Internet connection they have already paid for. That disruption is exactly what interests Robertson.

Change is good

"To me, the biggest opportunities are the areas where there's the largest change," Robertson said. "The largest change comes, when you're talking about technology, for those things that can be fully digitized, because you can leverage the amazing growth of the Internet.

"A cup of coffee can't be digitized, or tennis shoes or a car," Robertson said. "But music can -- that's MP3 -- software of course can be, that's what we're trying to do with digital distribution of Linux, and of course voice calls can be fully digitized, and that's what SIPPhone is all about."

Robertson has long been known for brashness. While at MP3.com, he openly taunted the music studios, and defied those who said naming a company after a technology was foolish.

"People said naming a company MP3.com was like naming your company Betamax.com, that you were going to be irrelevant, this technology was going to go away, better technology was going to come along," Robertson said.

The old standard

Today, Robertson noted, MP3 music is still the worldwide standard for digital music, such as in portable music players, despite competition from Microsoft, the digital media company Real, and the unrelenting hostility of music companies.

Now Robertson rarely misses a chance to criticize Microsoft as a bloated monopoly.

For its part, Microsoft has branded all versions of Linux a danger to commercial software, because of its peculiar nonproprietary licensing terms. Anyone can examine the Linux source code and modify it, but the source code and modifications must be made available at no charge.

Last year, Robertson himself was accused by Bradley Kuhn, executive director of the Boston-based Free Software Foundation, of not following the rules for Linux distributors. Although it is often described as "free" software, Linux can be sold, as Lindows is doing. However, its source code must also be made available for no cost, such as by downloading from the Internet.

The dispute was resolved later that year, and Lindows has continued introducing its products without incident. A call to Kuhn for comment was not returned by press time.

At the gates

More seriously, Microsoft last year filed a trademark infringement lawsuit against Lindows.com, claiming the name Lindows is too close to that of Microsoft Windows. Lindows won preliminary moves, and the case is due to go to trial in December. Lindows claims that Microsoft had no right to trademark Windows, because the word is a generic reference to a program's window on a computer monitor.

Even so, starting yet another company while the lawsuit remains in litigation and Microsoft's greater than 90 percent monopoly share remains intact might seem foolhardy.

"I figure if Steve Jobs can run Pixar and Apple, then I can run Lindows and SIPPhone," Robertson said, half-jokingly, half-jauntily.

More to the point, Robertson said Lindows is already being run by a "wonderful" president and chief operating officer, Kevin Carmony. That means Robertson is freed from day-to-day responsibilities.

Love of San Diego

Aside from technology, the San Diego area is one of Robertson's favorite subjects. He is not a native, having grown up in Orange County, but moved to San Diego about 15 years ago to attend UC San Diego. He graduated in 1990 with a B.A. in cognitive science.

After graduation, Robertson tried various jobs, including writing for the local computer magazine ComputorEdge, establishing a consulting firm based on the Macintosh computer market, and operating several Web sites.

Because he wanted to live in San Diego, Robertson said he resisted the advice of venture capital firms that advised him to move MP3.com to the Bay area. In addition, Robertson said he knew San Diego had a large number of technology-literate people who would like to remain there.

About four years ago, Robertson moved to Del Mar.

"I like it because it's a short commute to La Jolla, which is where MP3.com was, and where Lindows.com is. To me, the commute is the most important thing. And of course, Del Mar has a wonderful lifestyle, right there on the beach."

Contact staff writer Bradley J. Fikes at (760) 739-6641 or bfikes@nctimes.com.