The challenge with Postfix, or with any piece of software, is to update software without introducing problems.

Writing software that's safe even in the presence of bugs makes the challenge even more interesting.

This will surprise some of your readers, but my primary interest is not with computer security. I am primarily interested in writing software that works as intended.

However, writing software without defects is not sufficient. In my experience, it is at least as difficult to write software that is safe - that is, software that behaves reasonably under adverse conditions.

My whole career began because I was always putting my music on the Internet. By the time I had my first tour, I had an audience everywhere I went, because people were listening online.

Human beings are attracted to novelty: to probe the 'adjacent possible.' We didn't stay in the caves. We didn't stay on the planet, and soon we won't stay within the limitations of our biology. We move forward. We transcend our limits. We go to the moon, and we create the Internet.

I would not minimize the digital divide, which separates the computerized world from the rest, nor would I underestimate the importance of traditional books.

Many a fine SF story uses science or technology merely as backdrop. Many a fine SF story presumes a technological breakthrough and explores its implications without attempting to predict how the thing might actual work.