Remember VRML(The Virtual Reality Modelling Language)? The technology which was supposed to replace HTML in 1997 but never it did. I thought it with fancy virtual reality helmets in nineties. :)
But regarding to XML.com article it is still “alive” and it has transform to XML language called E3D.(Extensible 3D)
E3D models looks very impressive. Article: Extensible 3D: XML Meets VRML