SPLENDID is a federation implementation for distributed SPARQL endpoints.
SPLENDID is implemented as a Sesame2 Sail.
The Source Code can be found at code.google.com/p/rdffederator
Görlitz, Olaf; Staab, Steffen (2011): Federated Data Management and Query Optimization for Linked Open Data. In: Vakali, Athena; Jain, Lakhmi C.: New Directions in Web Data Management. Springer Verlag. S. 109-137.
SPLENDID development was started in the context of the CollaborationCloud project.