framework for Search and Retrieval by URL

 The SRU package provides a framework for working with the Search and
 Retrieval by URL (SRU) protocol developed by the Library of Congress. SRU
 defines a web service for searching databases containing metadata and
 objects. SRU often goes under the name SRW which is a SOAP version of the
 protocol. You can think of SRU as a RESTful version of SRW, since all the
 requests are simple URLs instead of XML documents being sent via some sort of
 transport layer.
 .
 You might be interested in SRU if you want to provide a generic API for
 searching a data repository and a mechanism for returning metadata records.
 SRU defines three verbs: explain, scan and searchRetrieve which define the
 requests and responses in a SRU interaction.
 .
 This set of modules attempts to provide a framework for building an SRU
 service. The distribution is made up of two sets of Perl modules: modules in
 the SRU::Request::* namespace which represent the three types of requests;
 and modules in the SRU::Response::* namespace which represent the various
 responses.