Read original post by Andrew Miadowicz at IEBlog
Thursday, May 31, 2012, we delivered the Windows 8 Release Preview and the Sixth IE10 Platform Preview. Windows 8 includes one HTML5 browsing engine that powers both browsing experiences (Metro style and desktop) as well as Metro style applications that use HTML5 and JavaScript. The release preview represents a major revision of the same modern JavaScript engine, Chakra, which first debuted with IE9. With each platform preview we make progress against our goals to create an engine that delivers great performance on the Web while ensuring that it is highly compatible, interoperable, and secure. This post will explore how the JavaScript engine has been enhanced to deliver great performance for emerging Web application scenarios.