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

In poor countries, we still need better ways to measure the effectiveness of the many government workers providing health services. They are the crucial link bringing tools such as vaccines and education to the people who need them most. How well trained are they? Are they showing up to work?

According to Ethiopian custom, parents wait to name a baby because children often die in the first weeks of life.

Bill Gates Quotes