Web.config

<?xml version="1.0"?>
<configuration>
  <system.web>
    <compilation debug="false" targetFramework="4.0"/>
  </system.web>
  <system.webServer>
    <staticContent>
      <mimeMap fileExtension=".geojson" mimeType="application/json"/>
      <mimeMap fileExtension=".gltf" mimeType="model/vnd.gltf+json"/>
    </staticContent>
    <httpProtocol>
      <customHeaders>
        <!-- Enable Cross Domain AJAX calls -->
        <remove name="Access-Control-Allow-Origin"/>
        <add name="Access-Control-Allow-Origin" value="*"/>
      </customHeaders>
    </httpProtocol>
    <rewrite>
      <rules>
        <rule name="removehtml" stopProcessing="true">
          <match url=".*"/>
          <conditions>
            <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true"/>
            <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true"/>
          </conditions>
          <action type="Rewrite" url="{R:0}.htm"/>
        </rule>
      </rules>
    </rewrite>
  </system.webServer>
</configuration>