The ALICE Off-line strategy a successful migration to OO

The ALICE experiment has chosen to start developing its software directly in OO, using the services of the ROOT system, which is ALICE’s candidate for the common LHC framework. This has lead to the definition of a complete environment (AliRoot) where the software developed by the different experimental groups is being integrated. Different test-benches for I/O and Simulation have been set up based on real production code. This allows early assessment of technology, both software and hardware, in a realistic production environment. Different codes such as GEANT 4, GEANT 3 and FLUKA, or the reconstruction algorithms by the physicists developing the detectors, can be easily integrated in the framework, which has shown to be both evolutive and modular. The ALICE Collaboration has adopted this setup and we are now successfully migrating the users into it. This talk describes the AliRoot environment and its future evolution.