The climate change and the recent extreme events occurred all over the world draw again the attention to the natural hazards both for prevention and for management aspects. In this context, environmental modelling can help in mapping hazards and risks zones and to support decision makers in building functional infrastructures with low environment impact and for a safe urban planning. In the last decades many researchers tried to extract useful information from digital data and in particular from Digital Terrain Models (DTM) with the development of ad-hoc algorithms and tools. In the meanwhile the data availability increased and high precision DTM are available almost all over the world. The algorithms contained in the HortonMachine library are the result of more than 10 years of research, development and real application of people from different research institutes and professionals working in the field of environmental engineering. The HortonMachine library contains tools for data management, data collection in the field, and environmental modelling in particular related to hillslope stability, floods, debris flow, forestry management and woody floods.