gistfile1.js

// ----------------------------------------------------------
// A short snippet for detecting versions of IE:
// Uses a combination of object detection and user-agent 
// sniffing.
// ----------------------------------------------------------
// If you're not in IE then:
//     ie === NaN  // falsy
// If you're in IE then you can determine which version:
//     ie === 7; // IE7
// Thus, to detect IE:
//     if (ie) {}
// And to detect the version:
//     ie === 6 // IE6
//     ie > 7 // IE8, IE9 ...
//     ie < 9 // Anything less than IE9
// ----------------------------------------------------------


var ie = ('ActiveXObject' in window && +(/\s(?:MSIE\s|rv\:)(\d+)/.exec(navigator.userAgent)[1])) || NaN

ie-mobile-detect.js

// The same thing but for IE Mobile instead.

var ieMobile = ( !! window.ActiveXObject && +( /IEMobile\/(\d+\.?(\d+)?)/.exec( navigator.userAgent )[1] ) ) || NaN;

Testing for 'mise' in the userAgent string will not work for version 11 as Microsoft has remove that string. The closest thing you might use is 'trident'. You also cannot use 'IEMobile' to detect Tablet mobile devices as they use a version of Windows for desktop. You should additionally be careful to properly detect both the RT and full desktop versions.