I don't think I had a backup plan at the time. I suppose I would have gone back to consulting and writing books. Maybe after a while I would have tried to start another company. That would have been hard, though, because if Viaweb hadn't worked out it would have been hard to talk Robert Morris into trying again.
I was pretty excited about Web apps, which were a new thing then. (We planned eventually to make a whole suite of them; Viaweb Store was just the first.) So I probably would have worked on those in some way. Maybe I would have written some sort of general platform for building them, and/or written a book about that topic.
Assuming the market hadn't changed, and you still had a big market for something like Viaweb, would you still use the same technology stack? Would you still use CLisp, or Clozure/SBCL/ABCL?
Are you asking what I'd use if I were building Viaweb today? The answer to that is probably Arc, though that says more about me than about currently available technologies.
I've kept an eye on Arc for years, with my 100-year language glasses on. How do you feel about Arc as the 100-year language as described in your essay? It's been 9 years since the essay; any plans for a followup, or do you feel that it's held up over time?
Clojure is probably the best bet. I don't know much about it but lots of people seem to use it, and any decent Lisp that lots of people use is probably a good bet.
Sorry for going off in a tangent but PG, would you consider doing an AMA on reddit. I've seen two posts in last week with the sole purpose of asking you a question. Seems like the community wants an interaction with you. If you've already done it, I couldn't find it.
There is a meaningful subset of HN'ers who have fairly direct access to PG and the other YC partners - the current class and alumni of Y-Combinator. For the rest of us, PG's essays cover a lot of his background as does his book Hackers and Painters.
The format of Ask PG seems to work pretty well. A mix of technical questions regarding YC applications, changes to HN, and interesting business questions tend to get deeper answers than is common within the limits of AMA.
I was pretty excited about Web apps, which were a new thing then. (We planned eventually to make a whole suite of them; Viaweb Store was just the first.) So I probably would have worked on those in some way. Maybe I would have written some sort of general platform for building them, and/or written a book about that topic.