  We present a new solver for massively parallel simulations of fully
three-dimensional multiphase flows. The solver runs on a variety of computer
architectures from laptops to supercomputers and on 65536 threads or more
(limited only by the availability to us of more threads). The code is wholly
written by the authors in Fortran 2003 and uses a domain decomposition strategy
for parallelization with MPI. The fluid interface solver is based on a parallel
implementation of the LCRM hybrid Front Tracking/Level Set method designed to
handle highly deforming interfaces with complex topology changes. We discuss
the implementation of this interface method and its particular suitability to
distributed processing where all operations are carried out locally on
distributed subdomains. We have developed parallel GMRES and Multigrid
iterative solvers suited to the linear systems arising from the implicit
solution of the fluid velocities and pressure in the presence of strong density
and viscosity discontinuities across fluid phases. Particular attention is
drawn to the details and performance of the parallel Multigrid solver. The code
includes modules for flow interaction with immersed solid objects, contact line
dynamics, species and thermal transport with phase change. Here, however, we
focus on the simulation of the canonical problem of drop splash onto a liquid
film and report on the parallel performance of the code on varying numbers of
threads. The 3D simulations were run on mesh resolutions up to $1024^3$ with
results at the higher resolutions showing the fine details and features of
droplet ejection, crown formation and rim instability observed under similar
experimental conditions. Keywords:
