A comprehensive software package, called ANALYZE, has been developed (1) which permits detailed investigation and evaluation of 3-D and 4-D biomedical images. The software is written entirely in "C" and runs on standard UNIX workstations. The software architecture permits systematic enhancements and upgrades which has fostered development of a readily expandible package. ANALYZE can be used with 3-D imaging modalities based on x-ray computed tomography, radionuclide emission tomography, ultrasound tomography, and magnetic resonance imaging. The ANALYZE package features integrated, complimentary tools for fully interactive display, manipulation and measurement of multi-dimensional image data. It provides an effective shell for custom software prototyping and turnkey applications. This paper provides a general description of this software with illustrations of its use, and provides specific details on the interactive volume rendering display module used for 3-D display.