Ramoonus

<p>This plugin adds the Modernizr to your WordPress installation.<br />
Modernizr is a small JavaScript library that detects the availability of native implementations for next-generation web technologies, i.e. features that stem from the HTML5 and CSS3 specifications. Many of these features are already implemented in at least one major browser (most of them in two or more), and what Modernizr does is, very simply, tell you whether the current browser has this feature natively implemented or not.</p>
<p>For documentation visit http://www.modernizr.com/docs/</p>


Modernizr for WordPress

The 2.8.4 version inserts broken javascript link.  I posted a message about this in the support section for the plugin and the author has not responded or fixed the problem.  Now, any site that I've added this plugin to can be broken if the user runs an update.  

Instead, if you need Modernizr, insert the following into your header.php file just after <?php wp_head(); ?>:

<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/modernizr/2.8.3/modernizr.min.js"></script>

Doesn't work - Plugin Defunct

This plugin adds the Modernizr to your WordPress installation.

Tigerton

<p>WordPress plugin that tell visitors to turn of IE compatibility mode if enabled.</p>
<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>
<p>Stay tuned as it possibly will get updated with new features.</p>


WP IE Compatibility Checker

Prompt users to turn off IE compatibility mode if enabled.

Modernizr for WordPress vs WP IE Compatibility Checker