While Internet Explorer 10 is practically always in Windows 8 (preview versions of the OS always included a preview version of IE), the last preview of IE10 for Windows 7 was released 14 months ago. Since then, preview versions have only been released for Windows 8. However, in a month, another preview version for Windows 7 will finally be released. After collecting and incorporating suggestions from users, the final version will be released.
There are really many new features in Internet Explorer 10. The biggest impact is probably the new HTML5 Quirks mode, which becomes the default mode of Compatibility View. CSS gradients*, *animations, gradients, and transformations as well as IndexedDB, font ligatures, and the requestAnimationFrame method can be used without the ms**- prefix, as they are stable specifications implemented in at least two browsers other than IE10. With the ms- prefix, it is possible to use CSS flexible box layout, grid layout, regions and device adaptation.
Internet Explorer 10 has seen a huge increase in performance in rendering and executing ECMAScript. Only those parts of the source code that will be executed ( JSMeter project from Microsoft Research) are compiled into bytecode. The compiler now supports x64 and ARM processor instructions. Calculations with floating point numbers are much faster. Access to object properties is much faster because the compiler gets an idea of the object’s properties. Memory reuse happens in the background, which is especially good for games. They usually create a large number of objects each render cycle and do not freeze (in the order of milliseconds) when old objects need to be removed from memory to make room for new ones.
The final version of Internet Explorer 10, which is in the final version of Windows 8, could hopefully be available for Windows 7 by the end of this year.
I wrote the article for Zdroják.