What about GD::Graph and related modules in that namespace.

A number of years ago I was using GD::Graph to emit daily reports from overnight regression tests. I was writing the graphs to the filesystem which where then served up as static files by Apache, however if you prefer you can generate your graph within a CGI script an serve it up directly in response to a CGI query.

I believe that it is possible to get GD::Graph to emit graphs in SVG form (instead of bitmap), by passing it a GD::SVG render surface, though I have never tried that.

Back in the day, I submitted a patch related to how graph axes where generated and where the tick marks would appear.