The Semantic Web (SW) is an extension to the current Web, enhancing the available information with semantics. RDF, one of the most prominent standards for representing meaning in the SW, offers a data model for referring to objects and their interrelations. Managing RDF documents, however, is a task that demands experience and expert understanding. Tools have been developed that alleviate this drawback and offer an interactive graphical visualization environment. This paper studies the visualization of RDF documents, a domain that exhibits many applications. The most prominent approaches are presented and a novel graph-based visualization software application is also demonstrated.