The CCP4 (Collaborative Computational Project, Number 4) software suite is a comprehensive collection of programs and libraries designed for macromolecular structure determination by X-ray crystallography. The suite is flexible, allowing users to achieve their goals through various methods. It includes around 200 programs, ranging from large packages to small 'jiffy' programs, and is connected by a common infrastructure using standard file formats, data objects, and graphical interfaces. Over the years, CCP4 has evolved significantly, with each major release featuring significant new software. The suite supports a wide range of tasks, from data processing and experimental phasing to molecular replacement, phase improvement, automated model building, refinement, and validation. Recent developments include the introduction of automation pipelines such as xia2, CRANK, MrBUMP, and BALBES, which can perform large sections of the structure solution process without user intervention. The graphical user interface ccp4i has also been a major innovation, providing a user-friendly way to manage and visualize data. Future plans include enhancing the suite's functionality for small molecule data management, improving the next-generation interface, and integrating crystallography with other techniques.The CCP4 (Collaborative Computational Project, Number 4) software suite is a comprehensive collection of programs and libraries designed for macromolecular structure determination by X-ray crystallography. The suite is flexible, allowing users to achieve their goals through various methods. It includes around 200 programs, ranging from large packages to small 'jiffy' programs, and is connected by a common infrastructure using standard file formats, data objects, and graphical interfaces. Over the years, CCP4 has evolved significantly, with each major release featuring significant new software. The suite supports a wide range of tasks, from data processing and experimental phasing to molecular replacement, phase improvement, automated model building, refinement, and validation. Recent developments include the introduction of automation pipelines such as xia2, CRANK, MrBUMP, and BALBES, which can perform large sections of the structure solution process without user intervention. The graphical user interface ccp4i has also been a major innovation, providing a user-friendly way to manage and visualize data. Future plans include enhancing the suite's functionality for small molecule data management, improving the next-generation interface, and integrating crystallography with other techniques.