HomeFilt - A Filter for Dynamic URL Redirection
If your URL contains only a slash for the site (i.e. http://yoursite/), then you've been redirected by HomeFilt. This ISAPI DLL redirects requests for the site's root to another URL, http://yoursite/SDK/HomeFilt/Home.Htm. And Home.Htm is what you are reading now.
See Default.Htm for the sample details.