Adding a new SOAP API

SOAP, Simple Object Access Protocol, is an XML-based messaging protocol that defines a set of rules for the exchange of structured data in a decentralized, distributed environment. It is not tied to any particular operating system or programming language. Thus clients and servers can be run on any platform and written in any language as long as they can formulate and understand SOAP messages. SOAP uses WSDL to describe the services that are exposed and can be used to generate the clients. So, what is WSDL, and what is a client? We will explain in the following sections.