We will continue to operate BioCARS, a nationally-available research resource for synchrotron-based macromolecular crystallography at the Advanced Photon Source, Argonne National Laboratory. The facility contains three experimental stations, one served by either an undulator or a wiggler insertion device source and two served by a bending magnet source, all of which can be used simultaneously. All stations and the associated control areas are embedded in a BL3-level biosafety facility, to permit the safe study of, for example, pathogenic human viruses. Research by users has successfully and productively concentrated on de novo structure determination by MAD phasing; on the collection of accurate, high resolution, monochromatic data; on the study of crystals with large unit cell dimensions; and on time-resolved crystallography on time scales down to a few nanoseconds. We will continue to emphasize these areas and to support the most challenging user experiments, through our experienced technical and scientific staff. In a facility that is unique nationally and one of three internationally, we will further develop time-resolved crystallography in both core and collaborative research, largely on the insertion device station. Advances in this scientific technique have led to much broader user interest in applying it to a wide variety of systems, since it offers new insights into biological mechanism and function. Upgrades will be made to the X-ray beam lines, both to replace those older components damaged by radiation and by heating and to afford smaller focal spots that are better matched to the smaller crystals that users wish to examine. Detector and data acquisition and control software will be improved, both to support collaborative projects in structural genomics that demand high data throughput, and to enable telecrystallography, in which the user can participate effectively in all aspects of the synchrotron experiment but need not be physically present at BioCARS. Strategies for improving the diffraction quality of crystals at both room and cryogenic temperatures by annealing will be implemented. In all cases, these developments are aimed at enhancing the throughput of excellent, high-resolution diffraction data and solved scientific problems, by satisfied users.