About the Platform Preview

March 16th, 2010

Today we’re excited to release the first ever Internet Explorer Platform Preview. 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.


When we released IE8, we said that our next steps started with listening to your feedback. A major part of what we heard, including comments to that same post, was that developers wanted more builds, more often. At the same time, given the high expectations of our users and the breadth of impact of changes we make to our platform, we need to carefully balance the quality of what we release with the frequency of releases. With the Platform Preview we want to strike a balance that provides developers an early and reliable hands-on experience with key parts of IE. With this Platform Preview, developers and people interested in standards and web development can try out new platform functionality and provide early feedback.

What It Is

The Internet Explorer Platform Preview is a light-weight frame around the core IE platform which includes the rendering and layout, object model, parsing, and script engines. It’s a way to try out the platform, and the experience improvements we’re making to performance, standards support and interoperability, enabling “the same markup” to work.

We designed the Platform Preview to be installed, side by side with IE8. The Platform Preview is not a replacement for your daily browser; for example, the Preview does not have an address bar, a back button, anti-phishing or malware protection. The Platform Preview does include debugging and diagnostics tools for developers. It also includes a way to provide feedback. The top level menus include Report Issue. You can find more information on how to use the Platform Preview in the User Guide.

This is the first Platform Preview. We will update it approximately every 8 weeks on the road to Beta. Each update will provide a more complete look at the IE9 platform. The Platform Preview along with these updates and the reporting tools are designed to speed up the feedback loop between developers and the IE platform.

What Developers Can Do

We ask that developers download and test drive the IE9 Platform Preview. We welcome feedback on how the Platform Preview works with your HTML, CSS, script, and other markup. We’ve provided a User Guide to help you make the most of the Platform Preview, as well as a Developer Guide with information about developing for the IE9 platform. The Preview’s start page is a Test Drive site with a set of samples that demonstrate some of what’s new in the platform. We want you to try the samples, look at the changes to the platform, and experience the new capabilities for yourself.

Some developers may already have sites that use the new capabilities. Other developers may write sample code to test out the functionality. In either case, we’d like to hear about your experience with the new features. Where possible, we’ve documented any known issues along with available workarounds in the Release Notes. In another blog post coming later today, we’ll talk about how you can best provide feedback.

We’re excited to be able to engage with our community in this way with the IE9 Platform Preview. We’re looking forward to seeing what developers build on top of the new platform, and to hear back from you about your experiences. Please check back on this blog and on the Test Drive site for information and updates in the coming weeks and months.

Justin Saint Clair
Program Manager