One family of visualization tools for the Semantic web are those that directly display the underlying RDF data. Most of them use the inherent graph structure of RDF data and present the user with some drawing of the graph.
While it is usually sufficient to give the user with decent understanding of data, there are some features of RDF that could be used to improve the visualization, for instance the presence of reifications. While they can easily be displayed just like any other part of the RDF graph, their specific properties allow for more advanced processing.