This project concerns the design, development, implementation, and testing of Grid services in the context of data intensive science applications on geographically distributed resources. We will investigate three strands in parallel, all with respect to High Energy Physics:

• A Data Grid Resource Broker, engineered to logically couple with data sources to perform online extraction data from closest data sources or replicas depending on user requirements. The broker selects data sources depending on their cost and user defined quality of services to optimize the use of resources. It evaluates whether to process on a resource where data is available by moving the application code, moving data to a resource where the application is available, or move the data and the application to a resource where computing power is most economically available.

• Defining and specifying physics experiments using a detailed, robust ontology enabling better interchange of services worldwide. The ontology will utilise concepts from HEP -- and computational resources involved in undertaking data analysis.

• A testbed for CERN analysis code related to the CERN Data Analysis Challenge.