Microsoft rolls out developer preview of IE11 on Windows 7

At Microsoft's Build conference, the IE team confirmed that Internet Explorer 11 (IE11) -- the latest version of Microsoft's IE browser that is baked into Windows 8.1 -- also will be available for Windows 7. About a month later, on July 25, the IE team made available a developer preview of IE11 for Windows 7, which includes a number of new F12 developer tools.

Windows 7 support is crucial for Microsoft, given there are more than 700 million Windows 7 users out there, according to the company. (In comparison, there are currently more than 100 million copies of Windows 8 that have been licensed, last we heard from Microsoft.)

The IE11 for Windows 7 developer preview is available for download today. The new developer preview also works on Windows Server 2008 R2. (Download center links are here, as well.)

IE11 for Windows 7 includes many, but not all, of the same features that are in the Windows 8.1 version, which is currently in public preview.

Here's what's different:

• In the Windows 7 version of IE11, the URL bar remains at the top of the browser (like it is with IE10 on Windows 7). IE11 for Windows 8.1 puts the URL bar at the bottom.
• Support for up to 100 simultaneously opened tabs per window isn't enabled in IE11 on Windows 7. (Officials said this is because IE11 on Windows 7 is a desktop/Win32 app, not a "modern"/Metro-Style one.)
• IE11 on Windows 7 won't support for premium video extensions like the 8.1 version does. "There are many solutions available for Windows 7 customers to stream and view protected content online, those methods will continue to function for customers," a spokesperson confirmed. (Read: Silverlight and Flash.)
• No support for Google's SPDY protocol (the precursor to HTTP 2.0) in IE11 on Windows 7. IE11 on Windows 8.1 does support SPDY.
• IE11 on Windows 7 will not support Enhanced Protected Mode browser security enhancements. (IE10 on Windows 7 didn't, either.)
• The UI Responsiveness tab is disabled in the F12 developer tools. However, support for this will be coming by the time the final version of IE11 for Windows 7 is released, thanks to "an update to the underlying Windows 7 platform."

Beyond this handful of differences, IE11 for Windows 7 and IE 11 for Windows 8.1 are largely the same, according to Microsoft officials. IE11 for Windows 7 includes the same improved performance, faster page-load times, new standards support and the revised F12 developer tools, a blog post on the IEBlog noted. Like IE11 on Windows 8.1, IE11 on Windows 7 includes support for WebGL. It will natively decode JPG images in real-time on the GPU so that pages load faster, use less memory and help improve battery life. It will support HTML5 link prefetching and pre-rendering. It incorporates changes to the "Chakra" JavaScript engine, including changes to garbage collection and just-in-time (JIT) compilation.

On the F12 tool front, the Windows 7 IE11 release adds some brand-new tools, including the aforementioned UI Responsiveness tool (which will be supported in IE11 on Windows 7 by the time it's released to the Web); new memory-profiling tools; Live DOM Explorer and CSS inspection tools to help with layout and rendering; and improved JavaScript debugging.

Microsoft also is updating today its modern.ie site, which is targeted at developers building sites and apps across multiple browsers and platforms. To attract developers to the site, Microsoft is renewing its 25 percent off on Parallels virtualization software deal. (The discount is available to the first 2,500 who grab Parallels Desktop 8 for Mac.) The site also adds an offer for free BrowserStack screenshot service, which allows developers to compare screenshots of their Web sites across ten different devices. And it is offering new VM images for IE11 on Windows 7 and Windows 8.1 to enable developers to more easily test sites on their Mac, Linux or Windows devices.

Microsoft officials are not saying when to expect the final version of IE11 for Windows 7 to be available. The final version of IE 11 for Windows 8.1 is on track to be released to manufacturing in August 2013, when 8.1 itself RTMs. And just in case anyone was wondering, Microsoft will not be making IE11 available to Windows 8 users because the company is assuming almost all of them will be updating to Windows 8.1.