The REACTION project will develop an integrated approach to improve long term management of diabetes, continuous blood glucose monitoring, clinical monitoring and intervention strategies, monitoring and predicting related disease indicators, complemented by education on life style factors such as obesity and exercise and, ultimately, automated closed-loop delivery of insulin. The REACTION platform will feature an interoperable peer-to-peer communication platform based on service oriented architecture (SOA) where all functionalities, including devices, are represented as services and applications consisting of a series of services orchestrated to perform a desired workflow. The REACTION platform also features a model driven application development environment based on extensive use of dynamic ontologies and advanced data management capabilities with algorithms for clinical assessment and rule-based data processing. The intelligent, interoperable platform developed by REACTION will provide integrated, professional management and therapy services to diabetic patients in different healthcare regimes across Europe, including 1) professional decision support for in-hospital environments, 2) safety monitoring for drug dosage and compliance, 3) long term management of patients in out-of-hospital environments, 4) care of acute diabetic conditions and 5) support for self management and life-style changes. A range of REACTION services will be developed targeted to insulin-dependent type 1 diabetic patients. The services aim to improve continuous blood glucose monitoring and insulin therapy, by both basal dose adjustment and contextualized glycaemic control based on patient activity, nutrition, administered drugs, etc. Decision support will assist healthcare professionals, patients and informal carers to better manage diabetes therapy and make correct choices about e.g. good blood glucose control, nutrition and exercise.