Bostick also says, "[At Pratt & Whitney] we have 10,000 software packages to help make rocket engines, but we use only one package [Outlook] to communicate."

From a security perspective, if Microsoft disappeared no one vendor would have a 95 percent market share and worms could not spread as fast. "Heterogeneity is a powerful positive," says John Pescattore, vice president for Internet security at Gartner.

We would also find out how bad the Linux and Apple vendors are at providing patches, compared to what [customers] got used to from Microsoft," Pescattore says, adding that Microsoft is much better than Apple and Linux at delivering security patches. "If you keep getting into car accidents, you know how to fix dents."

Marty Cooper, the man who invented the cell phone when he was at Motorola, thinks a world without Microsoft would be a disaster -- but only because we would have to learn somebody else's complex system. Cooper points out that you can get into a rental car anywhere in the world and just drive away, despite the fact that the automatic transmission is at least as complex as Office.

"Good technology is transparent and invisible," Cooper says, "and we haven't gotten there yet."