 This paper presents the <A NAME=tex2html2 HREF="http://www.cs.washington.edu/research/metacrawler">MetaCrawler</A>, a fielded Web service that  represents the next level up in the information ``food chain.''   The MetaCrawler provides a single, central interface for Web document searching.   Upon receiving a query, the MetaCrawler posts the query to multiple search services in parallel, collates the returned references, and loads those references to verify their existence and to ensure that they contain relevant information.  The MetaCrawler is sufficiently lightweight to reside on a user's machine, which facilitates customization, privacy, sophisticated filtering of references, and more. <P>
