As any web app designer that must keep up with standards knows, this can be quite challenging. You can build a web app and have it looking great in one browser, but when viewed in another browser it is completely unusable.

In the arena of AJAX the problem can be resolved by using AJAX libraries that were created by another developer that already ironed out the browser-specific issues. Although there are times we do need to create functionality from scratch, and as if on queue, these issues rear their ugly heads. When creating a site design from scratch, you get used to dealing with the CSS incompatibilities.

A lot of this could have been avoided if Microsoft could have just worked with Netscape back when XUL came out, 7 years ago (wow!). You see, AJAX is really just one big hack. Sure it's cool, but it's not pretty. The folks at Netscape saw the need for an XML-based UI language long ago and so they created XUL. Just search for XUL to find out more.