That's more advanced stuff than most web apps or frameworks do today. If viaweb had been done now instead of 15 years ago, they probably would have spun off lots of open source projects.
Doubtful. Yahoo rewrote Viaweb in C or C++, didn't they?
There's a reason why so many programmers still use CGI scripts. And why they depend on a host of scripting languages that rely on external libraries written by others.
Perhaps it's because they just don't grasp what Paul Graham is describing. They can't comprehend languages like Lisp or Forth or developing incrementally from an interpreter prompt.
And they don't need to. "Web 2.0" is an easy sell, no matter how crappy the "web apps" are, no matter what library-dependent, inflexible language they are written in. "Market forces" inhibit the few folks who do understand Lisp and Forth from spending more serious time with those languages.
The web browser as a UI. Brilliant. Programmers and end-users (a group to which programmers themselves belong) are getting smarter every day.
Anyway, you're right. It is definitely more advanced. Let's keep that in mind as we're looking at what's coming down the pipe hence forward and marvelling at what some will portray as "innovation".
That's more advanced stuff than most web apps or frameworks do today. If viaweb had been done now instead of 15 years ago, they probably would have spun off lots of open source projects.