Simple D3.js based tree example.
Source is available in the ./src directory. Just open the index.html in any browser to view the UI.
Nodes are connected in a d3 tree network, but with some hacking to allow cycles (so not a tree...).
Nodes are dynamic along vertical "depth" axes, but static in the x-direction.
Double click to toggle the fixing of node position.
Hovering over nodes highlights paths to (solid) and from (dashed) the node.
Hovering over arcs/links/paths (depending on nomenclature) highlights the start node (green) and the end node (red).