Microsoft Releases Second Preview Of IE10

Microsoft has released a second platform preview of its Internet Explorer 10 web browser.

On 29 June, 11 weeks after delivering the first IE10 preview at its MIX11 conference in Las Vegas, Microsoft delivered its IE10 Platform Preview 2 with support for site-ready HTML5 technologies and improved performance and security. The new IE10 build is available for download here.

In a blog post on the new release, Dean Hachamovitch, corporate vice president for Internet Explorer at Microsoft, said, “Developers will be able to build even more amazing sites and applications (beyond these or these) with IE10’s improved HTML5 support. As different browsers support developers using the same markup to achieve the same results with great performance, we can all realize the promise of HTML5 applications.”

With that in mind, Hachamovitch said Microsoft has posted over 270 new tests to the IE Test Center and submitted them to standards bodies.

New features and parsing improvements

Meanwhile, citing the IE10 developer guide, Hachamovitch listed some of the new features in IE10 Platform Preview 2, including the following:

• Beautiful and interactive web applications are easier to deliver with support for several new technologies like CSS3 Positioned Floats, HTML5 Drag-drop, File Reader API, Media Query Listeners and initial support for HTML5 Forms.
• HTML5 application performance improves across the board, as does the ability to deliver better performance with more efficient use of battery life with new technologies like Web Workers with Channel Messaging, Async script support and others.
• Web application security improves using the same markup with support for HTML5 Sandbox for iframe isolation.

Hachamovitch said the new IE10 Platform Preview includes parsing improvements from the W3C (World Wide Web Consortium) HTML5 spec, reflecting that developers can now expect the same behaviour in all compliant browsers even for imperfect or invalid markup.

HTML5 is the first version of HTML to define the behaviour of invalid markup, Hachamovitch said. “Rather than relying on “fix-up” rules that vary from browser to browser, HTML5 parsing behaviour is now specified in a way that developers can count on it,” he said. “IE10 now supports the File Reader API and HTML5 Forms validation, as well as advanced hit testing for more complex selection scenarios like graphics editors, games and other applications that typically use multiple graphics layers.”

Moreover, Hachamovitch says IE10 is the first browser to support several new performance APIs coming out of the W3C’s working groups. The test drives for setImmediate, requestAnimationFrame and PageVisibility illustrate how these APIs enable developers to make the web faster and more responsive even while websites make better use of battery life on mobile devices, he said. Meanwhile, web workers enable a host of new programming scenarios for the web, he added. With them, web applications can be more responsive by offloading complex JavaScript to run in the background, Hachamovitch said.

At the launch of the IE10 Platform Preview 1 in April, Microsoft said it would begin releasing new builds of IE10 every three months. Prior to that, Microsoft was releasing new IE builds every eight weeks.