1. Apparatus for responding to a request message sent from a remote user device for web page information by generating web page code capable of being interpreted by a browser within the remote user device for displaying one or more web pages and for outputting a response message comprising the web page code, the apparatus comprising: extracting means for extracting from the request message information determining a device type identifier identifying the remote user device which sent the request message as being one of a set of possible remote user device types having different capabilities of processing and displaying web page code; a processor for operating a code generating engine to generate the web page code; first memory means for storing the web page information as a content document comprising a set of instructions authored in a script language for generating the web page code; and second memory means for storing device dependent information for each of the set of possible remote user device types; wherein the code generating engine comprises interpreting means for interpreting the instructions authored in the script language with reference to selected device dependent information corresponding to the device type identifier of the remote user device which sent the request message, the code generating engine thereby being operable to generate the web page code in a form in which the web page code is tailored to the capabilities of the remote user device for processing and displaying web page code; wherein the content document comprises at least one component name identifying a respective data component, and wherein the apparatus comprises a data structure in which at least one data component exists as a set of data objects defining multiple versions of the data component where the data objects have different data properties suited to the different capabilities of processing and displaying web page code of the different remote user devices; and means for selecting a data object from the set of data objects identified by a component name for inclusion in the web page code on the basis of the device type identifier of the remote user device which sent the request message; wherein the selecting means is operable to look up a predetermined selection of data object using a component policy table in a case where selection of the version of data component for the remote user device is predetermined by an author of the content document, and wherein the selecting means is further operable to determine technical attributes of the remote user device and to select the data object by comparing the technical attributes with data properties of each data object in a case where no version of the data component for the remote user device has been predetermined by the author of the content document, wherein the technical attributes of the remote user device are defined in a device policy table.