This volume contains the proceedings of DAIS 2003, the 4th IFIP WG 6.1 - ternational Conference on Distributed Applications and Interoperable Systems. The conference was held in Paris on November 17 21, 2003. The event was the fourth meeting of this conference series, which is held roughly every two years. Previous editions were held in 1997 in Cottbus (Germany), in 1999 in Helsinki (Finland), and in 2001 in Krakow (Poland). Following the evolution of the ?eld, DAIS2003 focused on models, techno- gies and platforms for recon?gurable, scalable and adaptable distributed app- cations. In keeping with this focus, the call for papers especially encouraged original unpublished papers addressing the following topics: new/extendedsoftwarearchitecturesandframeworksforrecon?gurationand adaptation including component-based approaches (e.g., CORBA Com- nents, EJB, .NET), modelling, specifying, monitoring and management of context-aware and adaptive applications, support for recon?guration, self-organization and autonomic behavior in new/existing distributed platforms (e.g., CORBA, J2EE, .NET, WebS- vices), integration of multi-agent distributed decision-making, application environments that exploit characteristics of speci?c technologies (e.g., grid computing, mobile and wireless), issues in enterprise-wide and large-scale application recon?guration, semantic interoperability and semantic web services.