Java API for XML based RPC (JAX-RPC)

 JAX-RPC is an API for building Web services and clients that used remote
 procedure calls (RPC) and XML. Often used in a distributed client/server
 model, an RPC mechanism enables clients to execute procedures on other
 systems. In JAX-RPC, a remote procedure call is represented by an XML-based
 protocol such as SOAP. The SOAP specification defines envelope structure,
 encoding rules, and a convention for representing remote procedure calls
 and responses. These calls and responses are transmitted as SOAP messages
 over HTTP.