The graph is supplied as an SVG file. In Internet Explorer you must install the Adobe SVG Viewer plug-in to view it. Mozilla Firefox 1.5 (September 2005) will probably have native SVG support, it's already in the alpha version: Deer Park Alpha 2. Opera also has native SVG support.

An extra problem that may arise is caused by the fact that many Web Servers aren't configured to handle SVG files yet. They specify the wrong MIME type (txt) resulting in the source being shown instead of the graph.