MKSearch is a metadata search engine that indexes structured metadata in Web documents instead of free text in the document body. The data acquisition system conforms to the Dublin Core metadata in HTML recommendations, and supports other application profiles, such as the UK e-Government Metadata Standard. It also indexes native RDF formats, including RSS 1.0. The system has five major components: a Web crawler, an HTML document validator and formatter, a set of custom indexers, an RDF storage and query system, and a public query interface, provided through a standard servlet container.