I decided to test the website I'm working on now in older versions of IE (such as IE 6, 7, 8) using the IE Developer Tools aka F12. When I opened the Emulation tab in the Dev Tools dialog to set the document mode, I saw that we do not have different options for IE11 and Edge:

![enter image description here][1]

Does it mean that IE11 and the newest browser from Microsoft, Edge, use the same rendering engine? Or does it mean that the IE11 rendering engine has been updated through the Windows update automatically so even in Windows 8.1 in IE11 we are already using the newest rendering engine from Spartan/Edge from Windows 10? [1]: https://i.sstatic.net/br5Ul.png