Summary: A new free-surface flow model, RIPPLE, is summarized. RIPPLE obtains finite difference solutions for incompressible flow problems having significant surface tension forces at free surfaces of arbitrarily complex topology. The key innovation is the continuum surface force model, which represents surface tension as a localized volume force. Other features include a higher order momentum advection model, a volume- of-fluid free-surface treatment, and an efficient two-step projection solution method. RIPPLE’s unique capabilities are illustrated with two example problems: low-gravity jet-induced tank flow, and the collision and coalescence of two cylindrical rods.