An alternative approach to the maintenance of data loaders is federated data access with ad hoc queries. Federated information access solutions permit users to read/update data in multiple distributed data stores just as if data had been loaded into one database. Federated data integration and retrieval is very valuable for ad hoc querying and is also a good choice for conducting queries on data for which users have access permissions, but cannot move. Another use is for querying of large volumes of data to which users infrequently gain access, and a distributed approach can also be useful when disparate heterogeneous environments need support or when different parts of an organization require autonomy. One challenge of a federated approach arises because consistency between data models being queried is not required. When incompatibilities are found they have to be fixed and accompanying changes must be made. An innovative solution that allows scientists to gain access to integrated public data sources through one powerful SQL interface (without having to write data loaders or describe the data structure for a local database) is the RSS (Resource Description Framework or Site Summary and Really Simple Syndication) Gateway for Oracle from LION Bioscience. Other methods for enablement of semantic data interoperability discussed are Web services, and the Semantic Web (including use of resource description framework).