5. The structured document processing device according to claim 2 , further comprising: detecting means configured to detect a server and an operation on the basis of a request from a client in a Web service; and selecting means configured to select a most approximate structured document on the basis of the server and operation detected.
2. A structured-document processing device implemented on a computer, wherein the computer is configured as the structured-document processing device, comprising: storage means configured to store contents of both (i) a source structured document which has been parsed and (ii) a result of parsing structured partitions of the source structured document; matching check means configured to perform a matching check on whether or not source contents of the source structured document and contents of a new structured document match each other by comparing one of the structured partitions of the source structured document and a corresponding structured partition of the new structured document one by one in order starting from a head of both the source and new structured documents; classification means configured to classify each of the structured partitions of the new structured document into two categories, that is a first-class structured partition and a second- class structured partition, based on a result of performing the matching check concerning each of the structured partitions; parsing means configured to parse a structured partition which the classification means has classified as a second-class structured partition and generating a new parsed partition as a result of parsing the structured partition; and posting means configured to post to an application program (i) an event concerning each of the structured partitions in order from a structured partition in the head of the new structured document to a structured partition in a tail of the new structured document, (ii) an event concerning a source parsed partition of the source structured document corresponding to each of the structured partitions of the new structured document as a result of parsing the structured partition if the structured partition is a first-class structured partition, and (iii) an event concerning a new parsed partition concerning a structured partition as a result of parsing the structured partition if the structured partition is a second-class structured partition.