A major drawback of using SOAP for application integration is its enormous demand for network bandwidth. Compared to classical approaches, like Java-RMI and Corba, SOAP messages typically cause more than three times the network traffic. In this chapter we will explore compression strategies and give a detailed survey and evaluation of state of the art binary encoding techniques for SOAP. We also introduce a new experimental concept for SOAP compression based on differential encoding, which makes use of the commonly available WSDL description of a SOAP Web service. We not only conduct a detailed evaluation of compression effectiveness, but also provide the results of execution time measurements.