What Would The World Be Like Without Microsoft?

CanadianMikey asks: "The debate with the business side of computing rages on about the validity of Open Source. Is it good or bad? What is the future of computing? Could it have been different, and where will the 21st century take us? Is Microsoft just the big nail that always gets hammered first and will someone step in to take their place when they are finally taken down? If Microsoft were to close up shop, who do the readers of Slashdot think would be tomorrow's Microsoft? What about the forgotten windows?"