It was really phenomenal [Warren Buffett donation]. It grew out of the friendship that we had and the fact that his plan to have his wife run the foundation and give things away changed when she tragically died.

So we do software for watches, for phones, for TV sets, for cars. And some of these take a long time to catch on.

We're changing the world with technology.

I went to a public school through sixth grade, and being good at tests wasn't cool.

The close relationships we form between researchers and product groups have already shown we can move the great ideas as they come along, without a schedule, into the products.

I'm a big believer that as much as possible, and there's obviously political limitations, freedom of migration is a good thing.

I was announcing to the public, in 2006, that I'd be leaving Microsoft in a couple of years and focusing full-time on the foundation. That was the time at which we went back to New York and Warren [Buffett] announced these gifts to a number of foundations, with a very high percentage of it going to us and basically doubling our capacity.