The same thing that makes tech investing great also makes it frightening. I'm talking, of course, about disruptive innovations -- breakthroughs so transforming that they shatter industry conventions on the way to producing extraordinary wealth for the disruptors and, sometimes, bankruptcy for the disrupted. This idea is so powerful that Harvard Business School professor Clayton Christensen wrote a best-selling book about it called The Innovator's Dilemma.

As an investor in potential Rule Breakers, I tend to be on the lookout for developments that threaten to shake the foundations of fast-moving industries. This morning, I was thinking about -- what else? -- digital music. Blame CNET (NASDAQ:CNET). News.com reporter John Borland on Thursday wrote a compelling profile of a Silicon Valley start-up arrogantly named Pioneers of the Inevitable (pinky swear).

The company, it seems, hopes to topple Apple's (NASDAQ:AAPL) iTunes with an open-source alternative. The software -- called Songbird -- aims to take the emphasis away from a computer hard drive and toward the Web, and to design an interface that will work with a wide variety of music sites and services -- instead of just one, like, well, iTunes.

At the very least, the idea conjures images of the open-source Firefox browser and its bait and switch of a little bit of market share on Microsoft's (NASDAQ:MSFT) Internet Explorer. Which, in turn, offers more than a dollop of irony. Think about it: Apple's newest jewel chipped by the same technology that's made Mr. Softy turn soft?

Maybe. But that's only if the software actually reaches the market. Apparently, lots of programming work remains. Which leaves this site and its attendant screenshots all that eager open-source geeks will be able to get their hands on.

Still, if the stock market proves anything, it's that rules are made to be broken and that leaders are born to someday be followers. Remember Compaq? How about Informix? Silicon Graphics? Apple's time is yet to come. But it will. And when it does, don't be surprised if there's a little birdie nearby whistling a merry, open-source tune.

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High tech. Biotech. Nanotech. Any tech. David Gardner and his merry band of Foolish analysts cover it all for Motley Fool Rule Breakers subscribers. And they're profiting handsomely: The portfolio -- including CNET, a pick for the August issue -- is beating the market by more than 14% as of this writing. Get in on the action by taking a risk-free 30-day trial. Or sign up today and David will buy your copy of Stocks 2006 , which includes our analysts' best picks for the year ahead. Either way, all you have to lose is the prospect of better returns.

Microsoft is a Motley Fool Inside Value selection.

Fool contributor Tim Beyers hopes one day to borrow his wife's iPod. Yeah, we know: wishful thinking. Tim didn't own shares in any of the companies mentioned in this story at the time of publication. You can find out what's in his portfolio by checking Tim's Fool profile. The Motley Fool has an ironclad disclosure policy.