Coot is a molecular-graphics application designed for building and validating biological macromolecules. It supports various tasks such as model manipulation, validation, and refinement, with a focus on ease of use for novice users. The software integrates with external programs for advanced functionalities and offers scripting capabilities for expert users. Coot's user interface is designed to be intuitive and exploratory, allowing users to interact with the graphical display through mouse and keyboard controls. The program visualizes atomic models, electron-density maps, and generic graphical objects, and provides tools for model building, validation, and refinement. Recent developments have focused on enhancing the software for expert users, including customizable key bindings, extensions, and scripting interfaces. Coot is widely used in the crystallographic community and continues to evolve rapidly.Coot is a molecular-graphics application designed for building and validating biological macromolecules. It supports various tasks such as model manipulation, validation, and refinement, with a focus on ease of use for novice users. The software integrates with external programs for advanced functionalities and offers scripting capabilities for expert users. Coot's user interface is designed to be intuitive and exploratory, allowing users to interact with the graphical display through mouse and keyboard controls. The program visualizes atomic models, electron-density maps, and generic graphical objects, and provides tools for model building, validation, and refinement. Recent developments have focused on enhancing the software for expert users, including customizable key bindings, extensions, and scripting interfaces. Coot is widely used in the crystallographic community and continues to evolve rapidly.