Virtual Monte Carlo (VMC) defines a detector simulation framework that allows to run different simulation Monte Carlo without changing the user code and therefore the input and output format as well as the geometry and detector response definition.
This repository geant4_vmc includes the Geant4 VMC package implementing the Virtual Monte Carlo (VMC) interface for Geant4.
It also includes the G4Root package, which is independent from Geant4 VMC and can be build and used stand-alone, and VMC Examples, that can also be built independently and do not require Geant4 installation in case you want to run them with GEANT3.
Documentation: https://vmc-project.github.io
Reference: Geant4 VMC, G4Root, VMC Examples