gSOAP

The gSOAP toolkit provides a cross-platform software development toolkit for C and C++ server and client Web service applications, and simplifies the overall use of XML in any type of application. The toolkit supports SOAP 1.1/1.2 RPC 
encoding and document/literal styles, WSDL 1.1, MTOM/MIME/DIME attachments (streaming), SOAP-over-UDP, request-response and one-way messaging. The toolkit also supports WS-Addressing and WS-Security, with several other WS-* available or under development. See the official open-source gSOAP website http://gsoap2.sourceforge.net for project status and latest news.