CURRENT INTERESTS: Galaxy interactions, mergers and related star formation; galaxy formation and evolution in groups and clusters, and in the field. RECENT HST PROJECTS: Medium redshift galaxy cluster CL0939+4713; IIZw28 and the Cartwheel Galaxy; the globular clusters and GCLF of M87; WFPC2 and NICMOS snapshot surveys of ultraluminous IR galaxies; the Hubble Deep Field; both HDF GO STIS and NICMOS programs; HDF-South; STIS and NICMOS imaging of GRB 970508. OTHER PROJECTS: Used the VLA for snapshots of steep-spectrum radio sources; imaged some southern interacting and merging galaxies at CTIO. Via friendly observers, obtained some ESO 3.6m data on another galaxy merger. Also worked on polar ring galaxies, ground-based ULIRG imaging, and the HST GSC and images.