Things like IE scrollbars covering the content, word-wrap weirdness, designMode idiocy.. Differences in how iframes are handled - Things like that. Not to menti

Things like IE scrollbars covering the content, word-wrap weirdness, designMode idiocy.. Differences in how iframes are handled - Things like that. Not to mention all the IE6 rubbish like if you set left and right, it can't figure out width. "Most UI code written in JS is a variant of "find something in the DOM and change it"." I'd agree to a point, but I'd note that ideally you want to keep handy js references to what you have in the DOM so you don't have to find it again. And if you put it in the DOM, you don't ever have to find it, you just store it somewhere handy. Constantly performing search operations just isn't efficient.