Platform Improvements for IE8 Beta 2

We’ve been sharing plenty about the work we’ve done in Internet Explorer 8 Beta 2 for browser users we also want to share some of the notable advances we’ve made in the web developer platform in Beta 2. This post serves as an overview of the web platform changes since beta 1 that will be covered in more detail in the coming days and weeks.

The Layout Engine

First and foremost, we’ve been hard at work improving our standards support – we are now “CSS2.1 property complete,†meaning we’ve implemented every property in CSS 2.1 and are closing in on our goal of complete support for the CSS 2.1 specification by the time we release. This work includes improved support for many existing CSS 2.1 scenarios such as selectors, visual formatting (display, positioning and sizing) and text significant progress on the features first introduced in Beta 1 such as generated content, counters and outline and some new and improved features such as the CSS3 writing-mode property (currently behind –ms prefix.) In addition to the standards compliance work we have done, we have contributed more tests for the CSS 2.1 Test Suite including tests in support of the Accessibility Rich Internet Applications (WAI – ARIA) draft standard.

The Programmability Engine

We’ve also been improving our programmability engine. In addition to working on performance gains across the entire programmability stack, including in the core JavaScript engine, we’ve implemented mutability in our Document Object Model prototypes as well as attribute getters and setters in order to enable web developers and framework builders to extend our object model.

We’ve continued our Beta 1 investments in cross-domain requests (XDR) by working together with the Web Applications Working Group on improving the Access Control specification, and supporting it from XDR. This makes building interoperable cross-domain requests easier for everyone! Additionally, we updated our DOM Storage implementation to better align with the recent rounds of changes to the HTML 5.0 spec, especially in the localstorage method.

Last, but not least, we’ve added toSafeHTML/toJSON/fromJSON which is a set of code that sanitizes HTML and JSON content sent through the wire. It’s a great partner to the XDR (cross domain request) feature as well as HTML 5.0’s XDM (Cross Document Messaging) and delivers safer mashups to the user!

Developer Tools

While Beta 1 introduced the tools and provided helpful features like live HTML editing and a JScript debugger, Beta 2 is significantly more powerful with live editing of CSS, save to file, and console.log support. And because you need to make sure your site is not just correct, but fast, Beta 2 also includes a JScript profiler to help you find hotspots and compare design patterns. We’d love feedback on the tool and suggestions on ways to make it even more helpful.

In Closing…

With all the posts about the great things for the people who use the web with Beta 2, we wanted to remind those of you who build the web about the great opportunities you have to give visitors to your sites a fabulous experience. Moreover, we wanted to make sure that you developers had a reference (Internet Explorer Readiness Toolkit) checklist to vet against so your visitors to your site have a good experience as you ponder how to make it great with IE8. As always, you can find more information at the IE Development Center, http://msdn.microsoft.com/ie.

Thanks,

Doug Stamper

Lead Program Manager

Developer Experience

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