deformable-solids
SPlisHSPlasH is an open-source library for the physically-based simulation of fluids.
PositionBasedDynamics is a library for the physically-based simulation of rigid bodies, deformable solids and fluids.
Stark is a C++ and Python simulation _platform_ that provides easy access to state-of-the-art methods to robustly solve challenging simulations of rigid and/or deformable objects in a strongly coupled manner.