More IE8 Extensibility Improvements

We’ve made a few improvements to our extensibility model in IE8 RC1 based on feedback we’ve received both internally and externally.

WebBrowser (WebOC) Rendering Mode Changes

About a year ago, I posted an entry talking about WebBrowser Control Rendering Modes in IE8. You may recall that applications using the WebBrowser Control (also known as the WebOC, or Trident hosts) can use a Feature Control Key to select the default rendering mode of webpages they load.

Since our release of IE8 Beta 1, we’ve changed the name of the Feature Control Key that is used to toggle that behavior. The key was previously called FEATURE_NATIVE_DOCUMENT_MODE. IE8 now refers to it by the key FEATURE_BROWSER_EMULATION, and the values for both IE7 Standards Mode and IE8 Standards Mode have changed.

For compatibility purposes, the WebBrowser control will run in IE7 Standards Mode by default if no Feature Control Key value is defined for an application.

To run a WebBrowser control in IE8 Standards Mode, use the following new value into the registry:

[(HKEY_CURRENT_USER or HKEY_LOCAL_MACHINE)\Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION]
"MyApplication.exe" = dword 8000 (Hex: 0x1F40)

To run in IE7 Standards Mode, use the following registry value:

[(HKEY_CURRENT_USER or HKEY_LOCAL_MACHINE)\Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION]
"MyApplication.exe" = dword 7000 (Hex: 0x1B58)

For IE8 RTM, we’ve added a new “forced” IE8 Standards Mode value. When an application opts into this mode, the Web Browser control will use the IE8 User-Agent string and Browser Emulation mode strictly. It will also ignore fallback features such as the built-in Compatibility View list and the user-generated Compatibility View list when loading pages. To run in “forced” IE8 Standards Mode, use the following registry value:

[(HKEY_CURRENT_USER or HKEY_LOCAL_MACHINE)\Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION]
"MyApplication.exe" = dword 8888 (Hex: 0x22B8)

In all of these examples, “MyApplication.exe” refers to the name of your application.

Besides the control key name update for RTM, you may have noticed that these values differ from our Beta 1 release. If you are migrating your application from a Beta or RC1 build of IE to RTM, this value chart will help you replace old rendering mode settings:

  IE8 Beta 1 IE8 Beta 2 IE8 RC IE8 RTM

IE8 Standards Mode

80000 (0x13880) 8 8

8000 (0x1F40)

IE7 Standards Mode

70000 (0x11170) 7 7

7000 (0x1B58)

IE8 Standards Mode (Forced)

- - - 8888 (0x22B8)

For more information on how this will affect the way your application renders webpages, please refer to my older post, disregarding the old Feature Control Key information. If you would like to learn more about compatibility view and the differences between IE7 and IE8 modes, check out Scott’s post on Compatibility View.

ActiveX Logging Using the Application Compatibility Toolkit

The Application Compatibility Toolkit (ACT) helps customers understand their application compatibility situation by identifying which applications are compatible with Vista, IE7, and IE8, and which require further testing. To aid developers and IT Pros with ActiveX installations, we’ve added logging points for installation, instantiation, and loading of ActiveX controls. This data may help in determining whether or not a control is working properly, and may indicate if Line-of-Business applications need to be updated before IE8 is rolled out in enterprise scenarios.

For more information about how to use the Application Compatibility Toolkit, check out Jatinder’s post here. You can also take the toolkit out for a spin yourself by downloading it from

Deprecation of

A few years back, when ActiveX controls were first emerging as a web technology, Microsoft set up to allow for the distribution of popular controls.

As of IE8, Internet Explorer will no longer check for control installations and updates. From a technical standpoint, this means that the domain was removed from our default CODEBASE lookup locations; when attempting to download a control from webpages, this domain will no longer act as a fallback when no control location is provided or when a provided location fails.

Enterprises using their own codebase download paths will not be affected by this change.

Feedback and Suggestions

I love to hear from developers, IT Pros, and users about feature suggestions, comments, complaints, etc. As always, feel free to email me ( with your thoughts on how we can improve.

Matthew David Crowley
Program Manager
Internet Explorer Extensibility

Update 3/11: Added a sentence indicating that the WebBrowser control runs in IE7 Standards mode by default when there is no Feature Control Key defined.  Also, updated the registry values to indicate they apply in either HKCU or HKLM.