Repast is a suite of advanced, free, and open-source agent-based modeling toolkits designed to support the creation of flexible models for social science, biology, and other domains. It provides a range of features, including comprehensive model development and simulation capabilities, interactive visualization tools, and integration with other scientific computation libraries. Available for multiple platforms such as Java, .NET, and Python, Repast is widely used in both research and applied settings, offering users robust modeling capabilities to study complex adaptive systems.