I don't think you even need to wrap it, really. You need to make sure it's valid...

		int_19h 11 months ago \| parent \| context \| favorite \| on: Why can't HTML alone do includes? I don't think you even need to wrap it, really. You need to make sure it's valid XML, but the root element could be <html> just fine. And then use an identity transform with <xsl:output method="html">.