Database federation enables biological researchers to utilize resources more effectively, creating an environment in which the researcher can query multiple data sources without spending time learning new query mechanisms or issuing redundant queries which need to be integrated. Several mechanisms exist to federate databases. The ENQUire system is a network database federation system which uses a World-Wide-Web (WWW) interface to connect the users to various databases. Generic queries entered via a query generator form are sent in parallel to multiple databases, and the results are presented to the user in a unified format. All forms building, query generation, and results translation is done on the fly, and individual database translation modules can be added dynamically. ENQUire is a flexible answer to the problems of database federation on the WWW.