More than 30 years ago, Paul Allen and I started Microsoft because we wanted to be part of a movement to put a computer on every desk and in every home. Ten years ago, Melinda and I started our foundation because we want to be part of a different movement — this time, to help create a world where no one has to live on a dollar a day or die from a disease we know how to prevent. Creative capitalism can help make it happen. I hope more people will join the cause.