FusionCharts uses XML or JSON data to render the charts. In both data formats, the data file (or string) consists of data to be rendered, chart settings and cosmetics. FusionCharts XT has a specific XML structure for each chart and it does not depend on the server-side language.
To read and know more about specific XML structure, please refer to: http://www.fusioncharts.com/dev/usage-guide/getting-started/your-first-charts/using-xml-as-data-format.html