Don talks about his POV on AJAX, and brings up something that (to keep things simple) I neglected to mention in my post.

For a long time I have been deeply ambivalent about using DHTML and Javascript for serious apps. I really like the reach these apps create, the ease of distribution, and all the good stuff that comes from that. But aside from the problems that Don mentions in terms of pushing the browser "platform" beyond its design limits, I keep wondering about what writing complex applications using these technologies would do to software engineering in general. We have advanced quite a lot, and it's taken a lot of effort, to get away from error-prone techniques and tools that we used as recently as 5 years ago. Thanks to advanced IDEs, we are no longer bound by pre-existing structures and we're much more free to refactor, analyze, and reuse code in new ways. Java has been crucial in that (and in finally establishing how sensible memory-managed languages were), but now we're onto Python, PHP, Ruby, and other languages.

Going to DHTML and Javascript would put us back a bit in this evolution. Javascript and DHTML IDEs are basically non-existent or too basic. Debugging apps in a browser environment is a nightmare. Software maintenance becomes another nightmare. And so on.

But assumming that AJAX apps prosper, I think that we'll just circle back, realize that we're facing the same problems, and then find solutions based on our previous turn on this particular loop. Maybe this will another step towards what Marc Andreessen hoped (almost ten years ago, and I still remembering reading that article!): "A secure, truly mobile agent language -- way beyond Java -- will eliminate the Tower of Babel that prevents us from harvesting more of the benefits of computing and communications today."

Amen.