The evolution of IE from Internet Explorer 7 to Internet Explorer 8 spans from the graphical user interface on the surface of the browser to the underlying rendering engine. Among the various  improvements delivered to Internet Explorer, enhancing AJAX in the browser is an illustrative example of Microsoft's efforts to take its proprietary browser to the next level. In this regard, Sunava Dutta, IE Program Manager, revealed that the Redmond giant focused on improving AJAX for IE8, on top of what was made available with the Beta 1 release in March. The AJAX updates are already available as of the release of IE8 Beta 2.

“The good news is our team has been working since Beta 1 to tweak and update our implementations based on feedback from developers and ongoing updates to the W3C standards drafts on which most of these implementations are based or have been submitted for consideration. Not content with doing just that, we also added a few new features for developers. The AJAX updates we’ve chosen for Beta 2 focus on maintaining cross-browser compatibility and the feature sets that developers have thought would be the most useful,” Dutta explained.

The AJAX core development team has updated both XDomainRequest (XDR) and Cross-document Messaging (XDM), features designed to increase the security of cross-domain calls. At the same time with IE8 Beta 2, Microsoft has adopted W3C’s HTML 5 DOM Storage objects as a storage model, a move designed to bypass the limitations associated with the document.cookie property. In addition, IE8 developers will be able to use the navigator.onLine property and online/offline events both on Windows Vista and on Windows XP. Microsoft has also enhanced same-domain communications and cross-document messaging with improvements to XMLHttpRequest and ToStaticHTML.

“We’ve worked in standards to make the AJAX experience for developers better,” Dutta added. “Beta 2 implements the changes mentioned above. Moving forward, we will continue to partner with members in the W3C on a variety of topics including advancing draft specifications. Strong developer adoption of these features is a priority and we’re focusing on help sites transition to integrating these features. For code samples for the AJAX feature set, please refer to our IE8 AJAX Beta 2 Hands on Labs.”

Internet Explorer 8 (IE8) Beta 2 is available for download here.