Where do you see programming as a discipline in five, ten, or twenty years?
I think in the future programmers will increasingly use dynamic languages. You already see this now: everyone seems to be migrating to Ruby, which is more or less Lisp minus macros. And Perl 6, from n what I've heard, seems to be even more Lisplike. It's even going to have continuations.
Another trend I expect to see a lot of is Web-based applications. Microsoft managed to keep a lid on these for a surprisingly long time, by controlling the browser and making sure it couldn't do much. But now the genie is out of the bottle, and it's not going back in.
I don't think even now Microsoft realizes the danger they're in. They're worrying about Google. And they should. But they should worry even more about thousands of twenty year old hackers writing Ajax applications. Desktop software is going to become increasingly irrelevant.
What has your experience developing a new programming language, Arc, been like?
Interrupted. I haven't spent much time on it lately. Part of the problem is that I decided on an overambitious way of doing it. I'm going back to McCarthy's original axiomatic approach. The defining feature of Lisp, in his 1960 paper, was that it could be written in itself. The language spec wasn't a bunch of words. It was code.
Of course as soon as his grad students got hold of this theoretical construct and turned it into an actual programming language, that plan came to a halt. It had to, with the hardware available then. But with the much faster hardware we have now, you could have working code as the entire language spec.
I hope to get back to work on Arc soon. One of the reasons Y Combinator operates in 3-month cycles is that it leaves me some time to work on other stuff. (The other is that it's actually the right way to do seed investing.)