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'Developer Preview' of Internet Explorer 11 for Windows 7 Released

Web tools include a memory profiler, JavaScript debugger, DOM Explorer and CSS inspector.

• By Kurt Mackie
• 07/26/2013

Developers can now get their hands on the first preview version of Internet Explorer for Windows 7. While the preview version has new in-browser development tools, a number of the more advanced tools aren't available for Windows 7; instead, they're only for Windows 8.1.

This test version of the browser will run on Windows 7 Service Pack 1 or Windows Server 2008 R2 SP1, and can be downloaded here. The "developer preview" term appears to be a new one from Microsoft. This release appears to be a full browser beta. In the recent past, Microsoft had released so-called "platform previews" of IE that sometimes weren't full browsers.

This version of IE 11 was expected, as Microsoft had promised during its Build developer event last month that it would deliver a Windows 7 version. At Build, Microsoft had unveiled Windows 8.1, which also comes with a preview of IE 11. Users of the Windows 7 version of IE 11 can expect similar performance and standards support as found in the Windows 8.1 version of IE 11, according to Microsoft's announcement.

Feature Differences
However, some features don't coincide. The Windows 8.1 version of IE 11 supports SPDY, a Google-developed protocol aimed at reducing latency issues associated with delivering Web content, but there's no SPDY support in IE 11 for Windows 7. While IE 11 on Windows 8.1 supports Worldwide Web Consortium streaming media standards such as Media Source Extensions and Encrypted Media Extensions, those standards aren't supported on IE 11 on Windows 7.

In addition, Microsoft lists 12 features in IE 11 for Windows 8.1 that are not supported in IE 11 for Windows 7 at this "preview guide for developers" page. For instance, there's no native HTML 5 drag-and-drop support in IE 11 for Windows 7. A "UI Responsiveness" tool accessed via the F12 key is temporarily disabled in the IE 11 developer preview for Windows 7. Some of Microsoft's pinned site improvements aren't available and you can't sync browser tabs across devices with IE 11 for Windows 7.

Standards Support
Microsoft described achieving faster JavaScript performance with IE 11 for Windows 7 compared with its own IE 10 browser, as well as compared with Chrome, Firefox and Opera browsers. The Chakra JavaScript engine is improved and the Just In Time (JIT) compiler has a couple of improvements to reduce JavaScript computation times. IE 11 supports ECMAScript 6 and the ECMAScript Internationalization API 1.0.

Other standards support was previously announced, including support for WebGL, which uses the machine's graphics processing unit (GPU) to accelerate two-dimensional and three-dimensional graphics in a browser. While WebGL is currently being used in other browsers, Microsoft early on saw it as a security risk. Microsoft's announcement today stated that its implementation of WebGL in IE 11 will check for "unsafe WebGL content and implements a software-based renderer to complement the GPU." Microsoft claims that IE 11 verifies the hardware and GPU drivers as a security precaution when dealing with WebGL content and offers better recovery support on Windows.

"Unlike other systems, with Windows, failures in the graphics subsystem from unsafe content are not fatal, and WebGL continues to run," Microsoft claimed in its announcement.

Developer Tools
Microsoft indicated that it has redesigned some of the developer tools accessed in IE 11 through the F12 key. A new UI Responsiveness tool is designed to help developers quickly assess a Web page's frame rate and CPU use, although it's temporarily disabled in this developer preview release of IE 11 for Windows 7. Also included in IE 11 for Windows 7 are Memory Profiling tools, "Live DOM Explorer and CSS inspection tools," and JavaScript debugging tools. Microsoft claims that users of its F12 developer tools will get a similar user experience to Visual Studio in some cases. For instance, the F12 tools share Visual Studio's Intellisense feature.

Microsoft also updated its "modern.IE" portal of tools for Web developers. A BrowserStack scanning service accessed through that portal now can display screenshots of browsers rendering across various devices "from Windows to Mac to Android," according to Microsoft. BrowserStack is free to use for three months if a subscription is started up before Jan. 31, 2014, according to Microsoft's description. Microsoft also released its static code scanner, also called "modern.ie," into open source under the Apache 2.0 license, which is now distributed via GitHub.

Microsoft released some new virtual machine images for IE 11, both for Windows 7 and Windows 8.1. The images, which can be downloaded at the modern.IE page here, are designed to help developers test Web pages in their computing environments, including Android, Mac and Windows.

Microsoft is offering a limited promotional discount of 25 percent off for those buying Parallels Desktop 8 for Mac, which is virtualization software that lets users run Windows in a virtual machine on Mac computers. The deal is described at this blog post. The offer is available to the first 2,500 respondents before Aug. 19, 2013.