Microsoft have released the Windows Internet Explorer 9 Platform Preview, a pre-beta that delivers just a hint of what the next version of IE will offer.

Much of the focus is on performance, and it’s about time – IE has been trailing a long way behind the competition for years. In part this is to be addressed by a new script engine, code-named Chakra, which compiles JavaScript on one CPU core while the browser runs in parallel on the other. It’s an optimisation that sees the Platform Preview deliver much better performance on the Sunspider benchmark, which shows it leaping ahead of Firefox. Safari, Chrome and Opera 10.5 remain much faster, but then this is an early version: we’d expect the final IE9 to perform better still.

The Platform Preview is also making significant use of hardware accelerated graphics, offloading many complex rendering tasks to your graphics card for a further speed boost.

And the good news continues on web standards, with the Platform Preview including a number of demonstrations to show the progress made on HTML5, CSS3 and DOM. But it’s important to keep this in perspective. For example, the Acid3 test – a standard measure of support for web standards – shows the Platform Preview now scores 55/100, up from only 20 in IE8. It’s good to see some progress, but Firefox 3.7 scores 97/100 for the same test, so there’s plenty of work left to be done.

One less welcome development with the Platform Preview is that there’s no support for Windows XP: it’s strictly for Windows Vista and 7 users only. We’d guess this is at least in part due to the hardware accelerated graphics, which make heavy use of DirectX 2D, a technology that requires Windows Vista at a minimum. But the large numbers of Windows XP users out there aren’t likely to be impressed with the news that they’ll be stuck with IE8 forever, and so the IE9 release will probably see them migrate en masse to Firefox, Chrome or Opera.

If you’re running Vista or Windows 7, though, then you can now download the Platform Preview to try it out for yourself. Keep in mind that this is a pre-beta version, and extremely limited: there’s no toolbar, no security, not even a Back button. It is an interesting way to try out online benchmarks and web standards tests, though, and is designed to run alongside your existing IE setup so it’s safe to install.

There is one potential setup complication for Windows Vista users, though, and that again is due to DirectX 2D. If the Platform Preview complains that you don’t have this, then you’ll need to grab the update manually. Click Control Panel, go to System and Maintenance > Windows Update, and click on the Optional Updates link. Find and check the box for the Platform Update for Windows Vista, which contains the DirectX 2D libraries, then click OK. Once it’s downloaded and installed, reboot your PC, and you should now be able to install and run the Platform Preview.