Swift is a first-of-its-kind multiwavelength transient observatory for GRB astronomy. It has the optimum capabilities for the next breakthroughs in determining the origin of GRBs and their afterglows, as well as using bursts to probe the early Universe. Swift will also perform the first sensitive hard X-ray survey of the sky. The mission is being developed by an international collaboration and consists of three instruments, the Burst Alert Telescope (BAT), the X-Ray Telescope (XRT), and the Ultraviolet and Optical Telescope (UVOT). The BAT, a wide-field gamma-ray detector, will detect >100 GRBs per year with a sensitivity five times that of BATSE. The sensitive narrow-field XRT and UVOT will be autonomously slewed to the burst location in 20-75 s to determine 0.3-5.0" positions and perform optical, UV, and X-ray spectrophotometry. Strong education/public outreach and follow-up programs will help to engage the public and astronomical community. The Swift launch is planned for 2004. (C) 2004 Elsevier B.V. All rights reserved.