At the MIX10 Microsoft developer conference on Tuesday, Microsoft launched preview code for the most critical element of its Internet Explorer 9 Web browser: the underlying rendering engine. The new IE will feature hardware acceleration and new support for HTML 5 and scalable vector graphics, or SVG.

At the MIX10 Microsoft developer conference on Tuesday in Las Vegas, Microsoft launched preview code for the most critical element of its Internet Explorer 9 Web browser: the underlying rendering engine.

The key goals for the new browser engine are few and simple: improved speed, and support for new Web standards, particularly HTML 5 and SVG (scalable vector graphics).

IE9 isn't a full-fledged Web browser yet; so far, it's merely the rendering subsystems wrapped in a simple user interface that does nothing more than allow Web address entry and provides developer tools. at its Professional Developers Conference in November.

IE9's director Dean Hachamovitch told a select group of reporters last week at its Redmond, Washington campus that big changes were also coming to the browser's user interface, but that this release was aimed at giving developers a target for their website code.

The new Internet Explorer 9 browser platform will support a number of new standards, such as some parts of the HTML 5 spec and the SVG, or scalable vector graphics, standard, both overseen by the W3C organization, to which Microsoft contributes test code and other resources.

Internet Explorer has been something of an object of derision among browsers when it comes to speed, and particularly in JavaScript performance. The SunSpider JavaScript Benchmark results are often cited as an indication of this, but Microsoft has long maintained that it has placed its development efforts in other parts of the pipeline needed to render Web pages, such as layout and display. This version of Internet Explorer addresses both JavaScript and other speed bottlenecks.

Speed through GPU acceleration

Since much of what a browser does involves rendering graphical images and drawing them to the display, it seems logical that such operations would be performed on the hardware optimized for them: the graphics card. Current browsers, however, only use the CPU for these operations. IE9 moves graphics processing to the GPU (graphics processing unit).

IE9 will not only use the high-end gamer's powerhouse graphics card, but even those in low-powered machines. Though JavaScript performance plays a role in Web browser performance (as we'll discuss below), there are other factors, too: networking, HTML parsing, CSS, data collections, DOM (document object model), COM marshalling, layout, and display rendering. The IE dev team has profiled the most common performance patterns among thousands of the world's most popular sites, and found that rendering actually accounted for a bigger part of the pipeline than JavaScript. Clearly, handling the display rendering steps in the GPU will have a significant positive impact on Web performance.

JavaScript speed through compilation on a second core

Browsers handle JavaScript through on-the-fly interpretation, which, just like human language interpretation, requires steps between the code and the execution on the CPU. To be fair, what Firefox, Chrome, and Opera use is a bit better than straight-up interpretation; all of them use a JIT (just-in-time) compiler for some JavaScript, which does deliver palpable speed boost over interpreting the code.

But IE9 will go beyond the JIT idea, by taking advantage of the fact that nearly all PCs bought in the last few years have, in effect more than one CPU  they're dual-core or quad-core machines, usually  and use one core to render the JavaScript the old way and the second to actually compile it to run directly in machine code on the hardware, with no translation required. Any programmer knows that the speed difference between interpreted and compiled code is enormous, so it follows that in some cases the performance gain will be game-changing.

Jason Weber, the principal program manager lead for Internet Explorer, showed a demo of spinning 3D icons that dramatically illustrated the difference both JavaScript compilation and GPU graphics acceleration can make. As icons were added and spun faster, all current browsers topped out the CPU (or "pegged" it) and the spinning demo slowed down to a painful 5 or fewer frames per second with a dozen icons spinning slowly. But spinning and zooming 256 icon globes at warp speed in IE9 left the primary CPU core with processing time to burn.

"We're only using a quarter of the first core of the CPU," Weber said. "This is enabling developers to create a completely new class of applications on the Web."

The SunSpider benchmark only tests one element of browser performance, and it actually doesn't even test some of the most frequently used JavaScript commands. Microsoft has set up a test of the most frequently used ones on the test site for the new browser platform, and, though engineers were quick to deny the term "benchmark" for these, the results were impressive. For these top 15 JavaScript actions, IE9 came out twice as fast as the current SunSpider-leading Opera browser. Of course, we'll need to do our own tests to validate Microsoft's results, but, even so, it made for an effective demonstration.

Support for HTML 5

IE has a history of frustrating developers because of the need to fork parallel code, especially for earlier versions. Hachamovitch wanted to send the message that sites should just deliver one code base for all browsers that adhere to real standards. This comes back to what has been a programmer's Holy Grail for years: the concept of write-once, run-anywhere. One of the recurring themes at the press preview was IE9's goal of "browser interoperability."

And IE hasn't been alone in needing its own special code; Firefox has had the "-moz" prefix for some commands that only work in that browser, and Webkit, too, has required a "-Webkit" prefix for some as well.

Microsoft program manager Tony Ross demonstrated how a simple two lines of code to produce rounded corners on a rectangle quickly grew far more cumbersome when all the alternate code for the different browsers was added. "Ultimately, running the same markup and having complete interoperability is a two-way street: there's the part that the browser has to play, and the part developers have to play," Ross said. "We encourage them to detect for capabilities rather than for browsers."

Ross and other Microsoft engineers have been extremely active in the official standards body of the Internet, the W3C. Though tests like Acid3 have purported to indicate support for "standards," it turns out that many of the capabilities it tests aren't official W3C specs. Hachamovitch did note that "as we support more of the markup that websites are using, our Acid score will go up." But he went on to decry the test's claim to represent true standards, "As standards and browsers change, you see a lot of variance," he said.

With that said, the new browser engine's Acid3 score climbed from 20 to 55 out of 100 on the test, and that could still go up when we see a beta version.

A couple of specific HTML 5 features that the IE9 platform will support are the video and audio markup tags. And where Firefox hopes content providers will switch to the open-source Ogg formats, IE9 will support industry standard MPEG-4 and H.264 for video and AAC and MP3 for audio.

New support for SVG-scalable vector graphics Sure, you can offer a PDF download for complex content like floor plans and org charts, but why not make these decipherable right inside the Web page? SVG allows just that. SVG is a W3C standard for animated, interactive graphics based on paths rather than bitmaps. No matter how much you zoom in on an SVG image, edges remain razor sharpunlike bitmapped image formats like JPEG, which show degradation as you enlarge them. This holds true for text, too; that's key for the org-chart example mentioned above.

In fact, John Hrvatin, senior program manager lead for Internet Explorer, told journalists that IE9 is the first browser that natively supports SVG inline with HTMLpreviously XHTML was required. SVG is the descendant of VML, which came out of the . Other browsers use SVG for the popular map sites, while until version 9, IE has uses VML.

"SVG is a huge standard," said Visio veteran and now Internet Explorer partner program manager Ted Johnson. "We're not doing all of it in the first release, but we're doing a tremendous amount of it. When we ship, we're going to be covering all the way through what we consider 'static SVG.' Filter effects, animation, and fonts won't be included. A lot of these are still in flux. What's exciting about SVG is that you can easily see the markup in view source alongside its graphical result in the browser."

Will Microsoft get it right with IE9?

After years of criticism about IE's lack of support for standards and slower Web page rendering times than that of the competition, it looks like Microsoft is taking some concrete, drastic steps to address these issues.

Only time will tell, but Hachamovitch's plea to developers to stop coding separately for Internet Explorer is a good sign, as are the rendering speed initiatives. Taking advantage of today's ubiquitous multiple cores in the CPU and discrete graphics hardware is both a radical and yet a logical step, which could completely change the game when it comes to page-rendering speed. It will be interesting to see if other browser makers take the gauntlet and implement these techniques.

One factor, though, is the release schedule. Microsoft reps were completely non-committal about when the browser would be released, either in a beta version or a final version. Given the frequency of Google Chrome and Mozilla Firefox version releases, it's conceivable that another browser could come out with hardware acceleration before IE9.

For now, you can take the platform for a test drive by heading your current browser to Microsoft's IE9 test drive site. And stay tuned at PCMag.com for a full hands on and more background and analysis of this latest salvo in the browser wars from Redmond.