As this article describes:
They [Powerbuilder programmers] could do stuff quickly, or using the modern jargon, they were agile programmers without even knowing it.
Every Ajax intesive site I have been on besides Gmail locks up, bombs out and as another co-worker of mind (Ed Copony) says, "Ajax apps. make your computer fan go insane".
But I want to build a RIA app! I just don't want all the panic!
4-5 years ago building Flash GUI's was the rage for a bit. I never got a chance to do it & was admittedly against it in general. But suffering through Ajax makes one take another look. It is of course called Adobe Flex today & it seems to have come a long way. Certainly seems like a *productive* way to build RIAs. Sure you have to get past a couple hang ups, but that is life in the big city.
Hmmm, what can you do with Flex + JavaSpaces + Caching ... hmmm ...