I've been wanting to have a way to express RDF, create ontologies, use ontologies, perform SPARQL queries (and other queries), and see results in a visual way. It would look a lot like the node and arc diagrams presented in the Apache Jena Tutorial: "An Introduction to RDF and the Jena RDF API". Like they said, "RDF is best thought of in the form of node and arc diagrams".
One thing that might help with this, especially the querying part, is something like Tangible Functional Programming by Conal Elliott.
Other sources of inspiration might be Dr. Chris Weaver's Improvise Software. Dr. Weaver's Software is used for exploratory visualization. His software follows navigation coordination patterns which include things such as semantic zoom, synchronized scrolling, and scatter plot matrices. The software also allows for the construction of coordinated query graphs with the visual abstraction language coordinated queries.
Visual Abstraction is an interesting topic. Other sources found online include things such as: Chang et. al., "Visual Abstraction in the Visual Design Process", Burnett and Ambler, "Interactive Visual Data Abstraction in a Declarative Visual Programming Language"
Margaret Burnett has written a plethora of documents on Visual Programming. For example, here is one that appeared in the Encyclopedia of Electrical and Electronics Engineering.
Well this is a work in progress. I could be totally off.