Introduction ============ The Open Global Glacier Model (OGGM) is an open source modelling framework for glaciers. It has been developed since 2014: intermittently at first, and more regularly since 2016. Today, OGGM is continuously discussed and updated by a team of international researchers. Our main aim is to **assist the modelling of the evolution of mountains glaciers at large scales**. The OGGM framework offers various solutions to the challenges encountered when modelling a large number of glaciers. Here is a non-exhaustive list of its features: .. admonition:: **OGGM features** :class: info Data preprocessing Acquisition, download and processing of a large number of digital elevation models, gridded climate datasets, reference datasets for model calibration and validation such as geodetic mass balance and ice velocity products, and more... Climatic mass balance Mass balance models of various degrees of complexity, interchangeable, extendable and reprogrammable by anyone. Glacier geometry evolution models Suite of glacier evolution models of different types including toy models, statistical approaches (e.g. delta-h parameterization), and explicit approaches (including an ice dynamics module). Plug and play OGGM ships with a large set of pre-processed glacier states that can be downloaded and applied in modeling workflows using only a few lines of code. Distributed computing Automated and seamless task management system for efficient multiprocessing in cluster environments. Reproducible and sustainable code Well tested and well documented codebase, including online tutorials. Regularly maintained and freely available container environments for reproducibility across platforms and HPCs. Standard projections Pre-computed glacier change projections for a wide range of scenarios and use cases. See :doc:`download-projections` for more information. Community Welcoming community of users and developers: :ref:`get in touch ` and join us! Check out our `community website `_.