If you dabble in the stock market, you may be wondering whether it's time to dabble in Microsoft again. The market in technology stocks has come a long way back from the Internet bust -- some of the high flyers like eBay are flying again, and Google continues to defy gravity. Microsoft hasn't done nearly so well -- just before Thanksgiving it closed at $29.89 with the Vista launch in the wings and a pat on the head from the analysts at Credit Suisse. The last time the company's stock finished a day above $30 (adjusted for stock splits) was in April 2002 (chart here). So can Microsoft stock get hot now that Vista and Microsoft Office are shipping?

Vista hasn't given the stock much of a boost. It's fallen back a few cents since the week of Nov. 20, closing in the $29 to $29.50 range. Still, there's that Credit Suisse research research report. Analyst Jason Maynard forecast that Microsoft's share price would rise 20 percent, from $29 to $35, within a year. And he says Vista is why -- not necessarily because it's going to sell better than Windows XP, but because it comes in more higher-priced, feature-laden editions. He thinks, in fact, that revenue from Windows sales could grow 9 to 10 percent during the fiscal year.

Morningstar is similarly bullish. Its Web site soundbite: "Microsoft's upcoming product cycle will add another chapter to its long history of growth."

Even though analysts see some long-term upside to Microsoft, they aren't exactly raving about Vista. The features of Vista and Office 2007 are likely to be seen as nice-to-haves rather than must-haves, writes the Associated Press, and it quotes Forrester Research analyst Ted Schadler: "If you look at Vista, you say, 'What's the killer app?' Somebody else will build a killer app on it, but until you get a killer app, you don't see the power of the platform."

Analysts have been predicting slow adoption rates for Vista. Corporate customers will stretch test and deployment cycles out into 2008, according to many observers. Retail customers won't be any help, because historically they can't upgrade the OS that comes installed on their hardware. The bottom line seems to be that Vista will sell just as well as new PCs sell next year, which is expected to be a good year, but not insanely great.

I think The thing that makes Microsoft stock likely to hit $35 a share next year isn't Vista. It's Linux. It's not that Vista is good or bad, it's that nothing else is better. For a couple of years I've puzzled over why desktop Linux distributions haven't caught the public imagination. Free should be good, shouldn't it? But it still doesn't come installed on the hardware. End of story. And Macintosh sales are rocketing. But even a 100 percent increase in 2007 wouldn't make the Mac more than a bump on the Wintel sales curve (Macs could rise to capture 8.3 percent of the PC market by 2016, according to Needham & Co. analyst Charles Wolf -- and he's an optimist.

I think Schadler is onto something with that "killer app" theory -- but I'd turn it around: if we see anything like a killer app for either Mac OS X or Linux next year, Microsoft is toast.

I've heard theories on what the killer app might be -- a Linux-based media center, for one. (Apple could very easily steal this idea with a hardware-software package that would be a killer home media center. Unfortunately I'm afraid Steve Jobs is too tight with Hollywood to risk making the movie guys mad by encouraging home recording.) But with no killer app for the Linux platform, I guess my money stays on Microsoft.