It seems like you're interested in running multiple versions of your app using browser plugins. Running multiple versions of an app simultaneously can be useful for testing and compatibility purposes. As for running older versions of Internet Explorer like IE8 for testing, there are a few options you can consider: 1. IE Tab Extension: - IE Tab is an extension available for browsers like Chrome and Firefox that allows you to embed the IE rendering engine within a tab in your modern browser. - This extension can be helpful for quickly testing your website or app in an older version of Internet Explorer without needing to switch browsers. 2. Virtual Machines: - Using virtual machine software like Oracle VM VirtualBox or VMware...