Diagramming again

I think I may have posted draw.io before, by jgraph as a free demonstrator for their non-free JavaScript diagramming drop-in. The HNN thread, as usual, includes a few alternatives, none of which seem really to measure up. One commenter is using jgraph's code as part of his very cool InsightMaker tool, which uses the diagrammer to build a system, then runs simulations on that system to provide numerical graphs. (Now that is cool.)