KarstMod is a collaborative project developed by the French SNO Karst (http://www.sokarst.org/) from the INSU/CNRS, which aims to strengthen knowledge-sharing and promote cross-disciplinary research on karst systems at the national scale. The KarstMod platform provides an adjustable modelling platform for both the simulation of spring discharge at karst outlets and the analysis of the hydrodynamics of the compartments considered in the model. The platform also includes two optional modules: one to simulate snow precipitation and melt based on precipitation and temperature data; the other to calculate potential evapotranspiration from temperature data. The parameter of the modules can be optimized during calibration. KarstMod is a free software that comes with no warranty. You are welcome to redistribute it. Please refer to the license menu for distribution details. Contact: karstmod@services.cnrs.fr