We still need to run regular tests on older IE Versions as well. A solid tool to load multiple versions at once is IETester by DebugBar.

“IETester is a free (both for personal and professional usage) WebBrowser that allows you to have the rendering and javascript engines of IE10, IE9, IE8, IE7 IE 6 and IE5.5 on Windows 8 desktop, Windows 7, Vista and XP, as well as the installed IE in the same process. ”