The main idea behind the script is to go through the CSS rules and modify them to rules that IE understands and then wherever necessary add event handlers to support interactive pseudo classes like
:focus. There also other less CSS-related fixes like adding support for
ownerDocument in IE55.
Dean also emulates
max-height but I haven’t seen that in action and I’m not sure how this can be achieved with IE’s broken overflow model. I guess switching to overflow hidden might be acceptablt in a few cases but this will most likely not follow the standard.
Dean, if you read this you might want to look at our Box Sizing behavior.