WAIS10: The Wide Area Information Servers system was developed in cooperation by Apple Computer, Dow Jones and Thinking Machines Corp. (TMC) to provide a full-text information retrieval system for the Internet. The WAIS protocol is based on the draft ISO standard Z39.50 designed for bibliographic retrieval, with some necessary extensions for full-text searching. On the Internet, the role of WAIS servers is to generate inverted indexes on local documents and execute full-text searches on these indexes. TMC maintains a WAIS server which acts as a database of databases, allowing users to locate information sources (servers) on the Internet which may contain information relevant to their query. Although the WAIS protocol does not restrict the use of complex (e.g., boolean) queries, most WAIS servers today only supports simple keyword matching, forcing the user to refine queries by adding additional keywords.