This document describes the NISO Metasearch XML Gateway (MXG) protocol, which is based on the NISO-registered SRU protocol. This gateway provides a mechanism for information service providers to expose their content and services to a Metasearch engine. While the task group recognized that the longer term goal is some type of standardized query protocol based on SRU/SRW, an XML gateway provides an immediate, low entry barrier method for content providers to interact with metasearch services.
