InfoSleuth is an agent-based system that automates the gathering and analysis of dynamic, distributed data accessible over the web. To gather data, a user specifies an SQL query which references elements from a common domain ontology (i.e., terminology). Agents then locate resources that have advertised having data relevant to these elements and translate the ontology-based query into queries referencing elements in the different schemas of the identified local databases. Other agents then integrate the results returned from these multiple resources and express them in terms of the common ontology. The large amount of data returned may be overwhelming, and so analysis agents serve to filter and interpret it. InfoSleuth is implemented in Java, and includes a common agent shell and specializations of the shell. The system was developed within a research environment over the course of 5 years and is now being hardened for commercial applications.