1. A web service system allowing two or more web services to autonomously communicate in a conversation via documents, where the documents used by the two or more web services may require transformation, said system comprising: a plurality of conversation definition language (CDL) description files, wherein each of the respective CDL description files defines document types, transitions and interactions of a conversation; and a conversation controller controlling conversation for at least one web service and having access to the plurality of CDL description files, the conversation controller handling a plurality of inbound and outbound documents, and utilizing a plurality of CDL description files to determine document types for each of the inbound and outbound documents, and to determine transitions and interactions of a conversation, wherein the conversation controller is capable of utilizing a transformational CDL (TCDL) description file, the TCDL being a CDL extended with transformational elements.