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.

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

Software innovation, like almost every other kind of innovation, requires the ability to collaborate and share ideas with other people, and to sit down and talk with customers and get their feedback and understand their needs.

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.

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

The only thing I understand deeply, because in my teens I was thinking about it, and every year of my life, is software. So I'll never be hands-on on anything except software.