<i>Its incredibly important to web developers to be able to test IE, too. Helium needs a lot of extra work to support the older Internet Explorer browsers to patch around the missing features required. It will get done.</i><p>I cannot see why you should develop this for IE. This tool is no going to be used by end users. Developers are going to have Chrome/Safari or Firefox installed in their machines. Are there so many IE CSS hacks used in websites?