IE11 is coming along with Windows 8.1 preview. Today, IE11 is logged on to Windows 7, this platform provides the same complete and faster page loading speed as IE11 of Win8.1, more new standards support, and brand new F12 Developer Tools.
On the basis of compatibility, interoperability, and security, IE11 has greatly improved the performance of the JavaScript engine Chakra and added support for the ECMAScript 6 standard, including let, const, Map, Set, WeakMap, as _ proto _.
Microsoft provides JavaScript performance benchmark tests for IE11 and several other browsers. The tests use authoritative WebKit SunSpider testing software, and the platform is Windows 7. According to the test results, IE11 is 4% faster than IE10, and Chrome 28, Firefox 22, and Opera 15 are far behind.
Official IE11 Developer Preview download page:
Http://windows.microsoft.com/zh-cn/internet-explorer/ie-11-worldwide-languages