The Web as I envisaged it, we have not seen it yet. The future is still so much bigger than the past.

One way to think about the magnitude of the changes to come is to think about how you went about your business before powerful Web search engines. You probably wouldn't have imagined that a world of answers would be available to you in under a second. The next set of advances will have an different effect, but similar in magnitude.

What I do has to be a function of what I can do, not a function of what people ask me to do.

I'm an optimist about humanity in general, I suppose.

We need to look at the whole society and think, "Are we actually thinking about what we're doing as we go forward, and are we preserving the really important values that we have in society? Are we keeping it democratic, and open, and so on?"

The more you enter, the more you become locked in. Your social-networking site becomes a central platform - a closed silo of content, and one that does not give you full control over your information in it. The more this kind of architecture gains widespread use, the more the Web becomes fragmented, and the less we enjoy a single, universal information space.

Any good software engineer will tell you that a compiler and an interpreter are interchangeable.