In this paper we present parallel 2D and 3D finite element computation of u
nsteady, incompressible free-surface flows. The computations are based on t
he Deformable-Spatial-Domain/Stabilized Space-Time (DSD/SST) finite element
formulation, which takes automatically into account the motion of the free
surface. The free-surface height is governed by a kinematic free-surface c
ondition, which is also solved with a stabilized formulation. The meshes co
nsist of triangles in 2D and triangular-based prism elements in 3D. The mes
h update is achieved with general or special-purpose mesh moving schemes. A
s examples, 2D flow past spillway of a dam and 3D flow past a surface-pierc
ing circular cylinder are presented.