Tigerton

WordPress plugin that tell visitors to turn of IE compatibility mode if enabled.
<pre><code>Check if IE compatibility mode is enabled.
Write a custom popup text.
Select on what page types you want to enable popup. Example: only on front page or on all pages.
Select if you want visitors to be able to disable the popup for future visits.
Debug mode, to allowe the popup be displayed always, in any browser.
</code></pre>
Stay tuned as it possibly will get updated with new features.

WP IE Compatibility Checker

Prompt users to turn off IE compatibility mode if enabled.

canis1980

This plugin will send HTTP-headers to the client to ensure that Internet Explorer does not try to display the site in compatibility mode, 
which tends to break a lot of themes. This is the default behaviour for a lot of older Internet Explorer versions, when the site is identified 
as an intranet site. Some clients may also have the setting activated by other means.
This plugin will also tell Internet Explorer to start Chrome Frame, if that is present, as this will also enable the sites to display in a 
proper way.

Compatibility Mode Disabler

Disable Compatibility Mode in Internet Explorer for intranet sites. Also starts Chrome Frame if present.

WP IE Compatibility Checker vs Compatibility Mode Disabler