Thanks for reply, dsheroh.

I have never dreamed of such solution. I am going to try this.

I sometimes forget to describe what I am currently doing...
I am drawing wordnet graph on HTML. Currently, it is tree of 8 depth, around 2-3000 to 15000 synsets. I am so nervous for loading time because it is CGI.

Before I introduce SVG or GraphViz, I wanted to figure out 8 depth, 15000 synsets could be fetched, drawn smooth or not. I see my results, sadly, it is somewhat slow.

Now I was thinking of PathENum table of Joe Celko.

Thanks for your kind reply.
regards