Microsoft today released the Windows Internet Explorer Platform Preview to the public. The release is meant to demonstrate the capabilities of Internet Explorer 9 to Web developers while at the same time providing feedback to the IE9 team. Microsoft says it is committed to updating the Platform Preview to keep a more effective rhythm for discussion, and it will be updated every eight weeks or so. Microsoft will share feedback with standards-setting bodies in addition to using it for internal development.

The Platform Preview is a minimal wrapper: it's not a full-fledged browser. It has no tabs. It has no address bar. It has no back button. So what is included? Everything that Web developers need to see: the rendering engine, of course, as well as the new JavaScript engine, hardware acceleration features, and the developer tools. The IE9 team told Ars that each update will use one of the latest internal engineering builds, at which point the feedback loop will start again.

In short, Microsoft has found an alternative to having nightly builds, answering a long-standing criticism of its development process. Microsoft believes its solution is better, as it doesn't have the hitches that come with nightly builds.

We asked Microsoft why it chose eight weeks as the update period. "We found that eight weeks is the minimum amount of time for the feedback period to work and actually resolve issues," Dean Hachamovitch, general manager of IE told Ars.

Regardless of whether updates every eight weeks will be frequent enough, it is certainly an improvement over the IE team's previous stance of releasing one or two betas and one or two RCs over the space of many months.

In addition to the rendering engine, the Platform Preview has a start page where Microsoft showcases five Speed Demos, five HTML5 demos, and five Graphics Demos. Naturally they all work better, or at least as well, in IE9 as in any other browser; Microsoft isn't going to show off tests where its browser isn't as good as the competition. We were impressed with what Microsoft had to show off (we saw 28 tests in total, not 15), but there is still room for improvement. Microsoft agrees, which is why it is being a little more open about feedback and frequency of updates.

HTML5

"We love HTML5 so much that we want to do it right," Hachamovitch told Ars. Microsoft is putting a huge emphasis on HTML5 with IE9, but its approach is still very strict. Since HTML5 is not complete, and likely won't be anytime soon, the IE9 team is being very careful about which features it implements. Other browser makers aren't concerned about implementing a part of HTML5 one way in one version, then changing it in a subsequent version, and then changing it again... Redmond, on the other hand, is taking the same approach with IE9 as it did with IE8: support the current Web while pushing the new Web forward, according to Rob Mauceri, Principal Group Program Manager of IE. "Our approach to it is, let's really get the standard right," Mauceri told Ars. He admitted, however, that standards change and that it is quite likely there will be parts of HTML5 that change even after IE9 is released.

As you can see in the screenshot above, the IE9 team has made (some) progress in the Acid3 test. IE8 scores 20/100 on the test, and the IE9 build demonstrated at PDC scored 32/100, so given that the IE9 build from MIX10 is at 55/100, we can see Microsoft is certainly taking standards a lot more seriously.

The company's stance on the test, however, has not changed. Microsoft refuses to simply give in and implement everything the test requires to pass; the company continues to downplay the test as it barely encompasses HTML5 but instead tests some technologies that are still in the "working draft" stage of standardization, including many edge cases and error conditions. While Microsoft has no plans to score 100/100, it is not ignoring the test; instead, the company is focusing on what it believes developers actually want supported. "As we support more of the markup, our Acid3 score will go up," Hachamovitch told Ars.

Microsoft's stance is debatable. The Acid3 test, even if not that useful, is nonetheless influential. IE's continued mediocre score creates the perception that the browser is far behind its competitors, and will likely do little to lessen Web developers' dislike for the browser. It's also another barrier to convincing the world Microsoft truly cares about standards.

We did see one cool HTML5 feature we weren't expecting: IE9 working using YouTube's implementation of the HTML5 video element. This actually required a little tinkering on the part of the IE9 team, since the YouTube HTML5 Video Player has no support for browsers other than Chrome or Safari. Even so, it worked brilliantly. Microsoft admitted there is still a little work to do in this area, however, so today's release of the Platform Preview won't work with YouTube HTML5, but the software giant promised a later build will.

SVG

Speaking of implementing more features in later builds, let's take a look at Scalable Vector Graphics (SVG), an XML-based file format for describing static and dynamic 2D vector graphics. The 800-page standard has been in development by W3C since 1999, but only earlier this year did Microsoft join W3C's SVG working group and promise to collaborate on future versions of the standard. Now, the company is getting a little more specific about what it's going to support in IE9:

Functionality Platform Preview Internet Explorer 9 Document Structure Partial Yes Basic Shapes Yes Yes Paths Yes Yes Text Partial Yes Transforms Partial Yes Painting Filling Color Partial Yes Scripting Styling Partial Yes Gradients and Patterns Partial Yes Clipping and Masking No Yes Markers and Symbols No Yes Filter Effects No No Declarative Animation No No SVG Fonts No No

As you can see, only Basic Shapes and Paths are done today. Microsoft is promising to have a lot more done for the IE9 release, and while it has started most of those, it hasn't begun work on a few of them. Microsoft is not expecting to implement the last three in IE9 at all. The "Yes" in the IE9 column means that 95 to 100 percent of the implementation will be done, according to Microsoft. What Web developers have to know about the Platform Preview today is that SVG available on the Web will simply not look right, but Microsoft is promising to finish it to a point where it works.

When asked about SVG Fonts, which some other browsers implement, Microsoft answered that TrueType fonts work better, and so the company does not see it as a priority since there really is no need for yet another way to do fonts in SVG. SVG Fonts are very sophisticated in terms of API, but not very important in terms of uses out there, in Microsoft's eyes.

Microsoft cited the number of image editors and applications that currently have the option to output as SVG as one of the many reasons it decided to back the specification with IE9. The company also showed off how the included Developer Tools let you edit SVG just like editing HTML. That means developers can very easily debug problems with SVG.

"A lot of sites are sniffing for IE and rendering their content as Vector Markup Language (VML)," Patrick Dengler, Senior Program Manager of IE, explained. "We want them to stop doing that and start rendering as SVG." Development of the VML format ceased in 1998, but it's included in IE5 and higher. Microsoft even released a VML to SVG Migration Guide (880KB) today to help developers. As a result, many websites don't bother to check for the version of IE, and simply tell all versions not to render the SVG, something that will have to change with IE9. For example, Google Maps currently uses VML for vector paths when it detects IE and SVG for all other browsers.