I’ve posted before that Netview uses the version of Internet Explorer installed on your system. It turns out that, as of IE8, it’s not quite that simple. Thanks to Luc-Eric for pointing this out.

Netview is a hosted version of the Internet Explorer WebControl, and by default, the WebControl displays pages in IE7 Standards mode.

To force Netview to use IE9 mode, you can either set a registry entry

HKEY_LOCAL_MACHINE (or HKEY_CURRENT_USER)
     SOFTWARE
          Microsoft
               Internet Explorer
                    Main
                         FeatureControl
                              FEATURE_BROWSER_EMULATION
                                   xsi.exe = (DWORD) 000090000

or add this meta tag to your HTML page:

<meta http-equiv="X-UA-Compatible" content="IE=9" > 

I tested the registry entry, and after I set it, this browser detect page correctly said I was using IE9 (before I set the registry, it said I was using IE7).

Also, after setting the registry entry, Netview scored 140 at http://html5test.com/ (before I set the registry, Netview scored 40). Note that IE9 itself scores 141.