Distributed computing is one of the most important trends in IT which has recently gained significance for large-scale scientific applications. Distributed Analysis Environment (DIANE)  is a R&D study, focusing on semi-interactive parallel and remote data analysis and simulation, which has been conducted at CERN. DIANE provides necessary software infrastructure for parallel scientific applications in the master-worker model. Advanced error recovery policies, automatic book-keeping of distributed jobs and on-line monitoring and control tools are provided. DIANE makes a transparent use of a number of different middleware implementations such as load balancing service (LSF, PBS, GRID Resource Broker, Condor) and security service (GSI, Kerberos, openssh). A number of distributed Geant 4 simulations have been deployed and tested, ranging from interactive radiotherapy treatment planning using dedicated clusters in hospitals, to globally-distributed simulations of astrophysics experiments using the European Data Grid middleware. This paper describes the general concepts behind the DIANE framework and results of the first tests with distributed Geant 4 simulations.