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        Microsoft Releases Internet Explorer 10 Platform Preview 4
        
        
        
			- By Kurt Mackie
- November 30, 2011
Microsoft released the fourth version of its Internet  Explorer (IE) 10 platform preview Web browser prototype on Tuesday. 
These platform preview releases do not appear to follow a fixed schedule; rather, they occur whenever Microsoft's development team needs  feedback on browser features. The last IE 10 platform preview was included in the developer preview of the Windows 8 operating system, which Microsoft unveiled at its Build conference in mid-September.
To access platform preview 4, users must have  Windows 8 developer preview installed (it can be accessed here). Platform preview  4 won't run on Windows 7, although the final browser product will be designed  to run on both operating systems. Platform  preview 2 apparently was the last release that ran on its own, not  requiring Windows 8.
 
The new platform preview 4 adds some CSS 3, HTML 5 and DOM  changes for developers to test, according to Microsoft's revision history.  However, Microsoft's IE  blog is a bit more descriptive. One of the improvements involves  cross-origin resource sharing (CORS) technology. CORS facilitates file sharing  across domains using the XMLHttpRequest method. A demo shows how CORS can be  used to transfer files by dropping them onto a graphic.
 Another improvement in IE 10 platform preview 4 is new  support for text captions in HTML 5-encoded video streams. Microsoft describes  this improvement as "track captioning." Track-captioned text can  contain links, allowing users to click and move through a video, Microsoft  explained in the IE blog. 
 Developers can control which text at their Web sites is  selectable by users. Microsoft describes this feature in platform preview 4 as  "CSS user select support." 
 Microsoft updated its quirks mode in IE 10 platform preview  to work more like the quirks mode found in other browsers, such as Chrome,  Firefox, Safari and Opera.
 Microsoft also claims it has speeded up performance in IE 10  when combining the canvas element, gradients and opacity, scalable vector  graphics rendering, and hardware acceleration. A demo showing a cityscape with  falling raindrops formed through CSS transforms generated visuals at 60 frames  per second in the IE 10 platform preview 4 versus three to four frames per second when  running on Google Chrome.
 Microsoft claims that these improvements in the IE 10  platform preview 4 will apply not just to the Web pages parsed through  company's nascent browser, but they also apply to Metro-style applications  running on Windows 8.
 "The features in this platform preview are available to  Web pages now, and will be available to Metro style applications in Windows  8," Microsoft states in its IE blog.
 Platform preview 4 of IE 10 can be downloaded at Microsoft's  test-drive page here.  A guide for developers can be accessed at this page.
        
        
        
        
        
        
        
        
        
        
        
        
            
        
        
                
                    About the Author
                    
                
                    
                    Kurt Mackie is senior news producer for 1105 Media's Converge360 group.