Windows 8 is key to the future, the Surface computer.

During the past two centuries, innovation has more than doubled our life span and given us cheap energy and more food. If we project what the world will be like 10 years from now without continuing innovation in health, energy or food, the picture is dark.

The idea that you encourage companies to take their innovative thinkers and think about the most needy - even beyond the market opportunities - that's something that appropriately ought to be done.

Although I don't have a prescription for what others should do, I know I have been very fortunate and feel a responsibility to give back to society in a very significant way.

The human body is the most complex system ever created. The more we learn about it, the more appreciation we have about what a rich system it is.

A first-generation fortune is the most likely to be given away, but once a fortune is inherited it's less likely that a very high percentage will go back to society.

India has over 20 percent of the kids born in the world. And they move around a lot.