Cross browser compatibility used to just mean “does it work in non IE browsers”. With the new IE7 you now have to worry about it working in IE6 as well. IE7 fixed a lot of bugs that were in IE6 and seemed to have created some new ones. IE6 still commands a large lead over all other browsers.

The big problem with trying to test this is the fact that when you install IE7 you lose IE6. I found a nice program that fixes this. The program is called Multiple IE. They have another program that lets you install IE7 without removing IE6. I tried that and it caused a lot of problems on my computer.

Multiple IE has a few problems. It sometimes will crash and throw up some weird error boxes. It is not to be used as your main browser. I would only use it for testing. There are no problems when it comes to showing you what others will see on their screen. Just ignore any errors and use it for visual testing only.