Most of the challenges in developing Ajax applications is dealing with the developmentlifecycle of creating applications for the various browsers. Despite the fact that Dojo attempts abstracts away the pecularities of the various browser platforms, there are stillgoing to be cases where it works on one browser and not the other. So here is a list of someof the tools that I use and feel free to add your own as well.
I was pretty much resigned to the fact that I was going to have to use IE's MS Script Editor todo anything meaningful on IE, but then along came the IE Developer Toolbar which integrates intoIE 6 and IE 7. It's in Beta 3 right now so there are few problems, but it's a step in the right direction.