Cross browser compatibility plays a major part in producing any website or web application. We have to make sure our code is producing the desired results across several browsers. This includes different versions of Internet Explorer. When it comes to virtualization, VirtualBox by Oracle, is a great tool for cross browser testing.
For all of that IE testing goodness, VirtualBox will run on Windows, Mac and Linux! Another bonus! Fortunately, Microsoft has made it a little easier by providing Virtual Machines with some of the more current versions of Internet Explorer installed. Get ready for some testing!