But Microsoft Research (MSR) General Manager Kevin Schofield shrugs off the difficulty of designing technology for mass markets. "It's our job to understand user differences," he says.

The research arm of Microsoft Corp. devotes considerable resources to the job. It has 750 researchers in 67 functional groups, from algorithms to wireless, in six labs, from Redmond, Wash., to Beijing. Schofield calls MSR "the world's largest computer science department."

Indeed, the scope of activities within MSR is stunning. A lot of the research is what you might expect, with computer scientists dreaming up a new widget for mobile communication, a new search algorithm aimed at topping Google or some new way to make Windows more secure. But MSR also engages in long-term fundamental research that might never produce revenue.

For example, it is working with several medical labs on the application of pattern-matching algorithms -- which it developed to recognize spam -- to the design of AIDS vaccines. "The reason that HIV is so resistant to our immune system is because it gets in a host and throws off many new mutations, so your body can't get a good, robust immunity to it," Schofield says. That's the sort of strategy used by spammers. A trial vaccine based on Microsoft's algorithms has just begun in vitro testing.

Tortoise or hare?