"MOMO" software is a zero dimensional model that simulates the different processes affecting the speciation and the behavior of chemical contaminants in an homogeneous water reservoir. It was developed within the framework of the "Contaminants cycle and modeling" project of the BE department ("Biogeochemistry and Ecotoxicology") of Ifremer between 2000 and 2010. It was intended for work studying metallic and organic contaminants speciation in marine and estuarine waters. It can also be used to estimate parameters when experimental measurements are available and can be reproduced by the model. The model's assumptions, its design and its documentation are presented in the Thouvenin & Gonzalez report (2021). The program and data are stored in directories, including the FORTRAN software and the model data files, with examples of parameter files to describe the contaminants and of data files to describe the conditions of the environment.