David said:
That's because you're depending on libraries and development
platforms that were stupidly not coded to support web standards
(likely Microsoft products, in fact).
No, it's because not all web browsers support doing AJAX stuff the same way
and some of them don't support it at all.
I develop using Eclipse IDE with javascript, HTML, CSS, and XML on the
client and Java on the server. Not a Microsoft product in the whole bunch.
A web app does have to be usable in Microsoft's web browser though or it's
pretty much useless.
We support IE 6 and 7 and Firefox 1.5 and 2. That gives us a pretty high
percentage of coverage, but you still have to deal with presentation issues
not being the same in all browsers or being affected by the user's settings.
We are now doing some serious looking at flex which runs under the flash 9
engine. As long as you have a browser that supports flash everything works
the same and looks the same and the GUI is much more like a thick client app
instead of being limited to the standard HTML widgets. The biggest
advantage I am exploring about it is that data transfer from the server can
be done in a binary format that is much more compact and thus a lot faster
when you need to pull larger amounts of data.