This is XFML

Mark Pilgrim dives into XFML, with a nice description of how XFML can be used to describe content from different points of view, like looking into the center of a gemstone from each of its multiple faces (facets). As with the concept of topic maps, this example illustrates how description can be done post content publishing when you use a format like XFML. This is the power of what Peter V's created, coupled with the facetmap tool. The descriptions and relationships of content can be overlayed on top of the content. Nice description and example using facetmap.