As I mentioned in another topic, they are (or were) all passionate about programming. And they all worked on interesting projects. But that latter may be an artifact of my selection process; I had heard of them because they worked on interesting software and I chose them because that would be more interesting to read about. So there may be equally great programmers who've been toiling away, unnoticed, on boring software in the bowels of some big company, who you and I have never heard of.
subject: Coders at Work: What's so special among them