New Version 5!
Click here to go to the new version of XML/SWF Charts.
As of version 5.0, there isn't a dedicated PHP interface for this charts tool. However, PHP or any other scripting language can still be used with XML/SWF Charts (the XML version of the same tool).
For information on how to upgrade to XML/SWF Charts, please see this page.
For version 4.x of PHP/SWF Charts, please start from this page.