UCSF ChimeraX is a next-generation software for visualizing and analyzing molecular structures, density maps, 3D microscopy, and associated data. It addresses the challenges posed by large and diverse datasets from cutting-edge experimental methods, offering advanced rendering options and professional software design. Key features include interactive ambient occlusion for realistic depth perception, reliable molecular surface calculations, and new algorithms for depicting secondary structure using ribbons and curved cylinders. ChimeraX supports large datasets, including mmCIF files, and provides a hierarchical interface for complex models. It leverages modern hardware, including multiple CPU cores and GPUs, to enhance performance. The software is open-source, free for non-commercial use, and includes a toolshed for community development and distribution of new tools. ChimeraX aims to provide an integrated multiscale modeling environment, enabling researchers to interactively access, visualize, and analyze structural data from atomic to cellular scales.UCSF ChimeraX is a next-generation software for visualizing and analyzing molecular structures, density maps, 3D microscopy, and associated data. It addresses the challenges posed by large and diverse datasets from cutting-edge experimental methods, offering advanced rendering options and professional software design. Key features include interactive ambient occlusion for realistic depth perception, reliable molecular surface calculations, and new algorithms for depicting secondary structure using ribbons and curved cylinders. ChimeraX supports large datasets, including mmCIF files, and provides a hierarchical interface for complex models. It leverages modern hardware, including multiple CPU cores and GPUs, to enhance performance. The software is open-source, free for non-commercial use, and includes a toolshed for community development and distribution of new tools. ChimeraX aims to provide an integrated multiscale modeling environment, enabling researchers to interactively access, visualize, and analyze structural data from atomic to cellular scales.