Microsoft Offers Final Pre-Beta Peek at IE9

Developers have the chance to see the key improvements Microsoft has made to its next-generation browser, Internet Explorer 9

Before the beta version of Internet Explorer (IE) 9 arrives in September, developers can see a host of new enhancements Microsoft has made to its next generation web browser.

At the Microsoft Financial Analyst Meeting on 29 July, Microsoft’s chief operating officer, Kevin Turner, said Microsoft will deliver a beta of IE9 in September.

“We’re really excited about IE9, which will be beta and coming out in September,” Turner said.

Developer Preview

Since announcing its plans to deliver a next-generation browser known as IE9 at its MIX 2010 conference in March, Microsoft has released preview versions of IE9 for developers to test about every eight weeks or fewer. A new Platform Preview release now enables the company to make that eight-week time frame for getting a beta out in September.

Going by the progress Microsoft has made in its previous Platform Previews, you might expect to see enhancements to the company’s “same markup” strategy, improved browser performance, greater compatibility and compliance with standards, enhanced HTML5 support, more test cases, and improved Acid3 test scores. With IE9 Platform Preview 4 you get all that and more.

Yet perhaps the standout feature of the several new and improved ones is the integration of the IE9 JavaScript engine into the browser itself rather than being simply bolted on.

In an 4 August blog post on the new preview, Dean Hachamovitch, Microsoft’s general manager of Internet Explorer, said:

“The fourth Platform Preview moves the new JavaScript engine, codenamed Chakra, inside IE9 and brings them together into one single, integrated system.

Performance Increase

“Through this deep integration, the performance of real world websites significantly improves, and IE9 becomes the first browser to have a shared DOM between the browser and the script engine based on ECMAScript5. The benefits start with real-world performance and consistency.”

Hachamovitch said before the Chakra engine was integrated inside the browser, developers using script engines for various languages had to communicate through the Microsoft Component Object model (COM), which could cause performance problems. And each script engine had its own language-specific view of the Document Object model (DOM), which created discrepancies, he said.

IE9 Platform Preview 4 also supports modern Scalable Vector Graphics (SVG), improved WebKit SunSpider JavaScript benchmark results and an Acid3 test score of 95 out of 100. That is up from 83 out of 100 in IE9 Platform Preview 3.

With this preview, Microsoft also contributed 519 new tests to standards bodies, which brings the total number of tests contributed during IE9 development to 2,138.

The IE9 Platform Preview 4 can be downloaded here.