Navigation
Navigate around the graph by clicking and dragging. Zoom in or out with the mousewheel, or, if you're on some variety of fondleslab, touch gestures should work. Alternatively, use the zoom buttons underneath the graph.
Double-clicking anywhere on the graph will also zoom in on that location.
Filtering
The filters at the right of the page allow you to view a subset of the graph. The sliders will show only nodes with a given minimum Degree (number of edges) or edges with a weight above a certain threshold.
The Dropdowns allow you to filter to only certain types of nodes, or nodes falling under a particular category (Packt content nodes only). Finally, you can do a text search on the node labels (case insensitive).
The blue button will undo all the active filters and show the full graph again
Nodes
Clicking on a node will bring up another panel containing information about that node. Clicking on the title of the node in this panel will take you to the page associated with that node.
Also shown is a list of adjacent nodes, segmented into Packt content (split by category) or StackOverflowTags
Share and Enjoy
When you select a node, the right hand panel will also display a url which will display this graph, zoomed into the selected node.