Ciao Gianni,
i would try with SWF::Chart, it produces data that can be plotted in a variety of ways from an SWF file; see XML/SWF Charts Gallery for some examples. Unfortunately the Flash part is not open source, but it works really well and the licence is not expensive; there is also a free version with some limitations.

There are also SVG::TT::Graph or SVG::Template::Graph, but in that case you will need an SVG capable browser.