When Sun first launched its Java software in San Francisco eight years ago, chief technology officer Eric Schmidt excitedly showed me how a scrolling stock ticker could run on a PC. Whoop-de-do. It was the first of many instances when Java's reality seemed to be failing to live up to its promise, which was even then already being hyped.

But last Friday I spoke by phone with Sun's current software boss, Jonathan Schwartz, who made me think that we might finally be entering a new era of exciting Java-based technology. I spoke to him the day Sun's big Java One conference ended.

Schwartz says Java is poised to solve the problem of delivering digital content securely. This -- a challenge that has bedeviled the music and movie industries, among others -- is no minor matter. And such a route is not one that most of us expected Java to take. Of course it has already transformed the way enterprise software is written and operates, but that's a less compelling story, so now that I've mentioned it let's move on. Java basics:

Java is both a programming language and an operating environment for software. Its primary appeal is that, unlike most operating environments, it is designed to run on any kind of computer. That way, a software developer can create a program once, and it will work, regardless of whether the system is a PC or a cellphone.

The big news out of Java One was that both Hewlett-Packard and Dell announced they would start shipping the latest version of Java on all their PCs this fall. This is significant because Microsoft has thus far stymied Sun's efforts to deploy Java on PCs by refusing to keep up-to-date versions in the Windows operating system. This refusal is the subject of a continuing court case in which Microsoft so far has fared poorly, even as it continues to stonewall Java deployment. Sun has succeeded in bypassing Microsoft's obstinacy partly because of the stunning success it has had with Java on cell phones. About 100 million phones worldwide now contain Java. Schwartz claims that the number of Java-equipped cell phones sold this year will exceed the world's total sales of PCs. "To outship PCs is a vision we articulated five years ago," says Schwartz contentedly, "and we're there." PC follows phone: Think of it this way: the most popular personal computing environment, so to speak, has become something other than the PC. Now Dell and HP have pragmatically decided not to let their machines miss out on whatever software gets developed and sold on cell phones. Schwartz predicts that the rest of the PC industry will soon follow its two leaders, and Java will be on all PCs. "This," exults Schwartz, "opens up the platform for us to develop a secure PC platform for the delivery of digital content."

In this the personal computer is following the phone, which at least in Europe has become a wildly popular way to purchase digital content. Schwartz says the market for selling cell phone ringtones in Europe is now $1.6 billion annually. That figure stunned me. Turns out that the average ringtone sells for about $2.50, and some go for as much as $5. Many of these are excerpts of popular songs. In some countries the ringtone industry has become as large as the record industry. Put that in the pipe of the next person who says we're not in a new economy.

Music companies are happy to see their songs distributed as ringtones in part because the digital information is only playable by the purchaser. What ensures that is the "SIM" or subscriber identification module in each phone, which typically uses Java. The Java simcard identifies the user as authorized to use the content.

Java could hold key to music: Schwartz foresees a day when you will always use your SIM to listen to music. Any device that reads the card will be able to authenticate your right to listen to the music you've paid for, which of course will be available over the network. It could work with your network-connected home or car stereo or your TV, in addition to your PC and phone.

Explains Schwartz: "There are four things every person in the civilized world increasingly carries with them -- keys, money, a pen, and your phone." If you've always got your phone with you, you will likely have a Java SIM as well. Schwartz claims that PC companies will next start routinely including readers for Java smartcards in their machines. One of Dell's hottest laptops already includes a smartcard reader. Says Schwartz: "The inclusion of a smartcard reader effectively opens up the PC to be a secure platform for the delivery of digital rights to multimedia content -- music, video, games, news, you name it."

I don't know if this entire approach will work, but I know it's a new idea. While Sun hinted about this during the Java show, Schwartz says he hadn't explained it so thoroughly until our conversation. He doesn't pretend any of it is a fait accompli. "But once you start piecing together the trees in the strategy you begin to see a forest that is pretty interesting," he says.

Trouble for Microsoft?: If Sun's media strategy works, it could make Microsoft's failure to penetrate the cell phone market with its own software begin to seem more and more of a problem for the software giant. Sun does seem to be making progress promoting Java as the lingua franca for the mobile age. That's not good for the company that wants to make the operating systems for everything.

Sun launched a new consumer branding campaign for Java at its recent show and a new site, Java.com. Says the glib Schwartz, whose job appears to be as much marketing as software development: "This will enable us to jump out of just being a knuckle-dragging systems provider of network infrastructure and into the mainstream of consumer commerce and digital media." Hey, Jonathan—great positioning. So how does it all benefit Sun, a beleaguered company that still makes most of its profit (when there is any) by selling big honking servers? It's a question many ask. As they have for years, Schwartz and other Sun executives say the success of Java enlarges the potential market for their hardware and other software and thus their overall opportunity. Though nobody outside of Sun appears convinced that this is financially demonstrable, Schwartz is sanguine. "People asked me this week how we make money off it," he says. "My answer is that we have $5.5 billion more in cash today than we did when we invented Java. People may be confused about how we monetize Java. We're not."

Regardless of whether Java is good for Sun, it is increasingly good for the world. And it's not just for stock-tickers anymore.