Microsoft just launched a platform preview of Internet Explorer 10. As it is typical for Microsoft, this platform preview is meant to give developers a chance to test their software on the new rendering engine as it develops. The preview does not include any hint at what the user interface for IE10 will look like, however. The focus of this preview is on HTML5 and, according to Microsoft, IE10 “continues what IE9’s first preview began a year ago.”

Microsoft has only been working on IE10 for three weeks, but it already includes a new browsing engine that offers better support for various web technologies, including better support for the emerging CSS3 standard.

For those who keep score about these things, the platform preview scores 95/100 on the Acid 3 test. Running through the SunSpider JavaScript test a few times, the scores of the IE10 Platform Preview and IE9 were virtually identical.

Microsoft has also launched a number of new browser tests on its IE Test Drive site. Unsurprisingly, IE outperforms virtually every other browser in these tests.