one is not greater then the other (in some geeky kind of humour), one is different from the other
if you want to do this in FF, you could install the IE-tabs extension, not as good as FF-native (it relies on ActiveX to do this) but at least within FF
"If you are using any other operating system or browser please select Manual Download or click here to proceed."
Firefox is not the same as IE, hence it would be classified as "other browser". I don't know that Firefox is any "magnitudes greater" than IE. I'm currently using Firefox because I'm used to it and like the layout, but don't know that it is any better than IE or Opera. I've found they all have their pros and cons.