The vmc-project GitGub organization provides the following packages:
The core of the VMC provides the interfaces and classes independent from the Monte Carlo transport code.
See more in the VMC Core section.
The updated version of Geant3.21 that includes several bug fixes compared to the standard version in CERNLIB. The directory TGeant3 contains the classes which implement the TVirtualMC interface for Geant3
See more in the Geant3 section.
Geant4 VMC contains the classes which implement the TVirtualMC interface for Geant4.
For historical reasons, it also includes the G4Root package, which is independent from Geant4 VMC and can be built 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.
See more in the Geant4 VMC, G4Root and Examples sections.
In addition to these VMC packages, the vmc-project includes also the geometry conversion tool VGM and the VMC and VGM documentation repositories.