+$is_IIS = (strpos($_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS') !== false || strpos($_SERVER['SERVER_SOFTWARE'], 'ExpressionDevServer') !== false);
+
+/**
+ * Whether the server software is IIS 7.X
+ * @global bool $is_iis7
+ */
+$is_iis7 = (strpos($_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7.') !== false);
+