Paul and I, we never thought that we would make much money out of the thing. We just loved writing software.

When I say "miracle" I mean a kind of thing like a computer on a chip, or the internet, or the cellphone, that are really quite miraculous. Most people would not have predicted them, and their effect has been very, very dramatic.

An important re-engineering principle is that companies should focus on their core competence and outsource everything else.

Going out in the field, it's always enlightening to see what's working and what's not and to sit down and talk - I was with young girls in south Africa - understanding why our tools for prevention aren't being adopted, and what way may need to invent to help protect them.

I remember thinking quite logically that I didn't want to spoil my children with wealth and so that I would create a foundation, but not knowing exactly what it would focus on.

The answer is simple, and harsh. The market did not reward saving the lives of these children, and governments did not subsidize it. So the children died because their mothers and their fathers had no power in the market and no voice in the system.

Eventually we'll be able to sequence the human genome and replicate how nature did intelligence in a carbon-based system.