This volume contains the proceedings of FMOODS 2003, the 6th IFIP WG 6. 1 International Conference on Formal Methods for Open Object-Based Distributed Systems. The conference was held in Paris, France on November 19 21, 2003. The event was the sixth meeting of this conference series, which is held roughly every year and a half, the earlier events having been held in Paris, Canterbury, Florence, Stanford, and Twente. ThegoaloftheFMOODSseriesofconferencesistobringtogetherresearchers whose work encompasses three important and related ?elds: formal methods; distributed systems; object-based...