As seen here.
The vague plan is to write a front-end to GraphViz2 (which is a front-end to Graphviz) to do this sort of stuff, unless someone beat me to it.
And yes, I know Graphviz contains 'twopi'.
Does it have to be Perl? D3 is quite nice looking.
I agree D3 looks impressive, but I wanted to drive it from Perl, that's all.
I try to write all code in Perl, but find I end up writing in bash, CSS, HTML, JS, and SQL, and doing database design, just to get anything done...