Harnessing steam power required many innovations, as William Rosen chronicles in the book 'The Most Powerful Idea in the World.'

It's a nice reader, but there's nothing on the iPad I look at and say, 'Oh, I wish Microsoft had done it.'

We got a malaria initiative, really a phenomenal time, even though in the early stages there was some uncertainty. Then of course [Barack] Obama, although he had budget constraints, he believed in these things; a lot of new initiatives, including in agriculture.

You've got to be willing to read other people's code, then write your own, then have other people review your code.

China has many successful entrepreneurs and business people. I hope that more people of insight will put their talents to work to improve the lives of poor people in China and around the world, and seek solutions for them.

AIDS itself is subject to incredible stigma.

The world is not flat, and PCs are not, in the hierarchy of human needs, in the first five rungs.