An eventcloud is a distributed datastore that allows to store quadruples (RDF triples with context) and to manage events represented as quadruples. An eventcloud is based on a structured P2P overlay network combining high-performance elastic data processing infrastructure (grids, clouds), i.e. whose nodes acquisition and relinquishment can be dynamic and subject to a pay-per-use mode. Each node participating in the overlay networks will be responsible for managing the storage of subsets of the events, and will help in matching potential looked up events and disseminating them in a collaborative manner. As such, each node is also potentially an event broker responsible for managing subscriptions and routing notifications.