\defgroup pythia8 The Pythia8 interface \ingroup montecarlo \author T.Sjostrand. \brief The pythia8 directory is an interface to the C++ version of Pythia 8.1 event generators. The user is assumed to be familiar with the Pythia8 package. Only a basic interface to Pythia8 is provided. Because Pythia8 is also written in C++, its functions/classes can be called directly from a compiled C++ script. To call Pythia functions not available in this interface a dictionary must be generated. See pythia8.C for an example of use from ROOT interpreter.