This picure is a general schema of the AliRoot architecture.
The following picture shows an high-level decomposition of AliRoot into functional blocks.
This picture illustrates the concept of Virtual MonteCarlo schema as it is implemented by AliRoot.
This picture illustrates the stepping action mechanism for the virtual MC. Only the GEANT 3 version is operational, while the GEANT 4 one is under testing.
This picture illustrates the AliRoot flow of control.