On the second day of its MIX'10 conference in Las Vegas on Tuesday, Microsoft announced a pre-release version of Internet Explorer (IE) 9 aimed at web developers. Called the IE 9 Platform Preview, this pre-beta version of the browser provides no hints about any future UI changes—in fact, it doesn't provide a UI at all—but it does include an early looking at what appear to be impressive performance and interoperability improvements.

"Today we're excited to release the first ever Internet Explorer 9 Platform Preview," Microsoft General Manager Dean Hachamovitch wrote in a blog post describing the release. "The Platform Preview provides developers an early look at some of the features coming to Internet Explorer, enabling them to try out the new capabilities of the platform."

The developer focus in this release is obvious: The IE 9 Platform Preview ships without any browser "chrome" at all, and thus has no Back or Forward buttons, address bar, or other user-focused UI at all. Instead, it comes delivered in plain packaging, with just a window frame and simple menu.

But what it does provide is indeed interesting. With IE 9, Microsoft is promising to embrace the standards-based web in ways that surpass not just its own half-hearted attempts of the past but also the competition. And it will do so using hardware-accelerated rendering that will propel IE 9 well beyond the performance of other browsers.

With regards to standards compliance, Microsoft has committed to support a number of HTML 5 specifications, including Cascading Style Sheets (CSS) 3, Scalable Vector Graphics (SVG), XHTML parsing, and the HTML 5 video and audio tags with industry-standard H.264/MPEG4 video and MP3/AAC audio codecs.

IE 9 will also include a new JavaScript rendering engine, codenamed Chakra, which can utilize the multiple processor cores common to all PCs today to improve browser performance. Even more impressive, perhaps, is IE 9's ability to harness the graphical processing unit (GPU) found in all modern PCs to offload graphical rendering from the CPU, providing an even bigger performance bump. Today, all web browsers can utilize just a single processor core and have no interaction with the GPU; the performance delta between IE 9 and today's browsers is often staggering.

Developers who are interested in the Internet Explorer 9 Platform Preview can download this early version of the browser from the Microsoft website. (It doesn't replace your previous IE version, so it can be used for side-by-side testing.) I'll be providing a full write-up of this release later today on the SuperSite for Windows.