The way to be successful in the software world is to come up with breakthrough software, and so whether it's Microsoft Office or Windows, its pushing that forward. New ideas, surprising the marketplace, so good engineering and good business are one in the same.

Whether it's Google or Apple or free software, we've got some fantastic competitors and it keeps us on our toes.

Software substitution, whether it's for drivers or waiters or nurses - it's progressing. Technology over time will reduce demand for jobs, particularly at the lower end of skill set.

Microsoft Research has a thing called the Sense Cam that, as you walk around, it's taking photos all the time. And the software will filter and find the ones that are interesting without having to think, 'Let's get out the camera and get that shot.' You just have that, and software helps you pick what you want.

The truth of Moore's law has made remarkable things possible. On the software side, I think natural user interfaces in all their forms are equally significant.

I was lucky to be involved and get to contribute to something that was important, which is empowering people with software.