The UCSF Resource for Biocomputing, Visualization, and Informatics (RBVI) is pleased to announce the release of UCSF ChimeraX version 1.0! ChimeraX includes full user documentation and is free for noncommercial use. Download for Windows, Linux, and Mac OS X from: www.rbvi.ucsf.edu/chimerax/ Compared to Chimera, ChimeraX brings together: (A) significant performance and graphics enhancements - interactive display of very large atomic structures and maps - interactive ambient-occlusion lighting and/or directional shadows - fast and robust molecular surfaces - fast mmCIF reader (B) new implementations of Chimera’s most highly used tools - map fitting, segmentation, volume eraser, volume filtering - morph maps or atomic structures - play back volume series or atomic trajectories - view ligand-receptor docking results - find H-bonds, find contacts and clashes - virtual mutation, amino acid sidechain rotamers - radial coloring, coloring by map value - coloring by molecular lipophilicity potential, B-factor, etc. - animatable 2D labels and arrows - shape command to draw spheres, cylinders, etc. - sequence viewer with sequence-structure crosstalk - interface to Modeller comparative modeling (C) entirely new features - tube (curved cylinder) helices in cartoons - chain-chain contact diagram - H-bond or crosslink length histogram - built-in HTML browser with mechanism for click-to-execute commands (D) support for new areas - virtual reality - light-sheet microscopy - medical imaging data (E) major ease-of-use advances - toolbar with icons to perform actions with a single click - basic "undo" - more logical commands and more powerful command-line specification (F) a web repository (ChimeraX Toolshed) for developers to contribute plugins