  This volume contains the proceedings of RULE 2009: the tenth International
Workshop on Rule-Based Programming. It took place in June 28th 2009, Brasilia,
Brazil, as a satellite event of RDP 2009. The first Rule workshop was held in
Montreal in 2000, and subsequent editions took place in Firenze, Pittsburgh,
Valencia, Aachen, Nara, Seattle, Paris, and Hagenberg.
