FoxE9 is an add-on for Firefox that skins the browser and makes it look like Internet Explorer 9 in appearance. There are two perfectly legitimate reasons why anybody would want to do that.
1. Unlike its predecessors, IE9 has an attractive interface. It’s understandable if one wishes to have the same interface on Firefox.
2. You want your parents to embrace Firefox and all its open source goodness but they are resilient to change. You can secretly change Firefox’s appearance to resemble IE9, replace IE9’s shortcut with Firefox and your parents will never know.
FoxE9 turns this
For comparison, here is how the actual IE9 interface looks like.
Pretty good, huh?