IE 10 JavaScript improvements in Windows 8 explained

[visualbuffs]

The new version of Internet Explorer 10 that's part of the recently released Windows 8 Release Preview OS included a number of changes and additions; that includes improvements made in running JavaScript-based applications found on websites. In the newest post on the official Internet Explorer blog, Microsoft goes into a lot of detail about how the IE 10 team has made improvements in JavaScript performance.
Web sites, even ones that don't have a lot of interactive features, still might use JavaScript for features like social networking or running banner ads. Microsoft states that IE 10 runs on a revised version of the JavaScript engine Chakra, which was first launched in IE 9. For the launch of IE 10, the blog states that the Internet Explorer team evaluated a number of popular JavaScript website simulations as well as games such as Angry Birds and Cut The Rope. The blog states:

All of the applications are driven by a high frequency timer callback. Most of them use canvas for rendering, but some rely on animating DOM elements, and some use a combination of the two. In most applications at least portions of the code are written in the object oriented style – either in application code or in included libraries (for example, Box2d.js). Short functions are common, as are frequent property reads and writes, and polymorphism. All of the applications perform floating point arithmetic and many allocate a fair amount of memory putting pressure on the garbage collector. These common patterns became the focus of our performance work in IE10.

The rest of the blog post goes over, in highly technical detail, some of the improvements Microsoft has made to JavaScript. That includes adding 64-bit and ARM support to Chakra's Just-in-Time compiler, improving the floating point math functions and enhancements to IE 10's memory allocator and garbage collection. Microsoft says that all of that work has resulted in "dramatic performance gains for JavaScript-intensive applications, particularly HTML5 games and simulations" for IE 10.



Source: Internet Explorer blog | Image via Microsoft