Mesa is an Apache2 licensed agent-based modeling (or ABM) framework in Python. It allows users to quickly create agent-based models using built-in core components (such as spatial grids and agent schedulers) or customized implementations; visualize them using a browser-based interface; and analyze their results using Python’s data analysis tools. Its goal is to provide an ecosystem to support generative science approaches, improve understanding of complex systems and aid practical decision-making.