In a wireless portal system having a wireless server, a client aware Extensible Markup Language (XML) content integration and transformation method and system. The client aware XML content integration and transformation system includes logic for identifying wireless client devices connecting to the wireless server by using particular characteristics of the client in presenting XML content formatted in response to connection requests from the client to the server. In one embodiment of the present invention, the client aware XML content transformation system receives an indication of a client type and uses this information to automatically search for XML content from a plurality of back-end resource servers on the Internet and transforms the content into a format suitable for delivery to the client. The means of formatting the XML content uses a style sheet such as an Extensible Style sheet Language (XSL) specific to the client type of the client requesting the XML content to transform the XML content into an appropriate markup to the client.