Under the auspices of its Euratom Research Framework Programmes, the European Commission (EC) has supported the development of the RODOS (Real-time On-line DecisiOn Support) system for off-site emergency management after nuclear accidents for more than a decade. Significant additional funds have been provided by many national research programmes, research institutes and industrial collaborators. In particular, the German Ministry of Environment, Nature Conservation and Reactor Safety financially contributed to the project with emphasis on early emergency response. The final result of these collaborative actions, the comprehensive RODOS system, can be applied generally within and across Europe. It can be used in national or regional nuclear emergency centres, provides coherent support at all stages of an accident, and, includes the long-term management and restoration of contaminated areas. It is the only Decision support system so far combining terrestrial and aquatic assessment models at one place. In its newest JAVA based version named JRodos), the system can be applied world wide and has users in more than 10 European and Asian countries.