Opera 11 beta has just seen the light of day, and another innovative idea which has been implemented into this desktop browser would be tab stacking. In order to create a stack, all you need to do is drag-and-drop a tab onto another, where hovering a stack will provide you with a visual overview on what’s happening in the stack itself. Said stack can be expanded or collapsed with but a click. Opening plenty of tabs in a single browser window might not be new to many of us, but we do know that doing so does tax your machine quite a bit – especially if you’re running it from a laptop or notebook. Tab stacking is how Opera reponds to the Panorama (initially called Tab Candy) introduced in Firefox 4.0, so we’re keeping our eyes peeled on whether Google will include something similar in their next Chrome update.