Everything you need to get started with Geant4.
Geant4 source code and installers are available for download, with source code under an open source license.
Documentation for Geant4, along with tutorials and guides, are available online.
Please make sure to cite the following papers if you use Geant4:
- Recent Developments in Geant4, J. Allison et al., Nucl. Instrum. Meth. A 835 (2016) 186-225
- Geant4 Developments and Applications, J. Allison et al., IEEE Trans. Nucl. Sci. 53 (2006) 270-278
- Geant4 - A Simulation Toolkit, S. Agostinelli et al., Nucl. Instrum. Meth. A 506 (2003) 250-303