Inside every large graph is a small graph dying to get out.<p>There's a place for just wanting to see everything, but the beauty of graphs is abstraction. Sometimes if you are asking a specific questions, a small, beautiful graph might be a better way to answer the question, than just rendering a diagram with hundreds or thousands of objects.<p>Graphviz just provides a basic rendering service; it would be up to higher semantic layers to support such exploration. Also, no doubt, interactivity is essential. It would be good for some enterprise that has the incentives to support the work, to create a new system, or at least to extend Graphviz to support better interactivity. It is not such a big stretch.