1. A method for executing Card Application Toolkit (CAT) commands on a portable data carrier, comprising the steps of: receiving command information relating to at least one CAT command from a terminal through a web server of the portable data carrier; executing the at least one CAT command through a CAT interpreter of the data carrier, wherein the command information is embedded in an HTTP command request message of an HTTP client of the terminal; and through the web server of the portable data carrier, carrying out the steps of: identifying the received command information in the HTTP command request message; identifying as command information in the HTTP command request message at least one CAT command or a reference to a file containing at least one CAT command and stored on the data carrier; extracting the received command information from the HTTP command request message; and relaying the command information to the CAT interpreter of the data carrier for execution of the at least one CAT command, wherein the data communication between the data carrier and the terminal is carried out on the transport layer according to the Bearer Independent Protocol (BIP), the portable data carrier does not comprise a Java runtime environment, and the data carrier does not have to support a complete Internet protocol stack.