I believe innovation is the most powerful force for change in the world. People who are pessimistic about the future tend to extrapolate from the present in a straight line. But innovation fundamentally shifts the trajectory of development.

I think it's fair to say that personal computers have become the most empowering tool we've ever created. They're tools of communication, they're tools of creativity, and they can be shaped by their user.

Some people, through luck and skill, end up with a lot of assets. If you're good at kicking a ball, writing software, investing in stocks, it pays extremely well.

In 1990, one in 10 children died before the age of five. That's now down to one in 20, and vaccines were the single biggest factor in that. Had it stayed at 10 percent, 122 million more children would have died.

The difference between a stranger sending you a message that you might be interested in at a very low volume level, no repetition, just sending it to very few people, and that being done as spam - those things get close enough that you want to be careful never to filter out something that's legitimate.

No one person controls Microsoft. The board and the shareholders decide whether they want to have me as CEO.

There are more people dying of malaria than any specific cancer.