A query runtime architecture and an exemplary application programming interface suitable for the architecture are presented. The architecture inputs one or more XML queries and views and enables the queries to be translated wherein the queries and views may be run over multiple data sources of different data models. The architecture incorporates front-end compilers which convert input queries and views into an intermediate language representation which represents the meaning of the respective query or view. The architecture may then allow the back-end compiling of the intermediate language representation to target languages compatible with the data sources desired to be queried. The architecture also allows the execution of those target compilations to extract the data requested of the queries. The invention also discloses an example application programming interface for the query runtime system.