In this chapter, we describe the BabelPeers project. The idea of this project is to develop a system for Grid resource description and matching, which is semantically rich while maintaining scalability and reliability. This is achieved by the distribution of resource data over a p2p network, combined with sophisticated mechanisms for query processing, reasoning, and load balancing.

We start by describing the benefits of semantically expressive languages for Grid resource description, and then continue to explain our methods, and how they help to maintain scalability. This includes distributed data storage and query processing strategies. Reliability is given by replication in the p2p network. Special emphasis is given on novel methods for load balancing and efficient query processing. Finally, we present benchmarks and simulations to show the good performance of the BabelPeers system.