GLG4sim is a Generic Liquid-scintillator Anti-Neutrino Detector ("GenericLAND") Geant4 simulation. It has a lot of features that you won't get just by editing the Geant4 examples. The initial version of GLG4sim was derived from the most general parts of KGL4sim, a Geant4-based Monte Carlo for KamLAND. (See ACKNOWLEDGMENTS.) This code is being made available to the neutrino physics community in the hope it will be useful and in the belief that code of general interest to the scientific community should be shared freely among researchers whenever possible.