Geant4 is independent of any histogramming package. The Geant4 toolkit has no drivers for histogramming, and no drivers are needed in Geant4 to use a histogramming package. The code for generating histograms on some of the distributed examples should be compliant with the AIDA abstract interfaces for Data Analysis. Consequently, you may use your favourite package together with the Geant4 toolkit. Please refer to the JAS documentation on histogramming for using the JAVA Analysis Studio tool. Please refer to the iAIDA (an implementation of AIDA in C++) documentation : tool for generating histograms with AIDA to HBook, Root and AIDA-native compressed XML format. Please refer to the Open Scientist Lab documentation on histogramming for using the Lab Analysis plug-in for the OnX package. Please refer to the rAIDA documentation (a Root implementation of AIDA): Root plugin for generating histograms with AIDA. Examples in Geant4 showing how to use AIDA compliant tools for histogramming are available in the code distribution in the following directories: geant4/examples/extended/analysis, geant4/examples/extended/electromagnetic geant4/examples/advanced