Laghos: High-order Lagrangian hydrodynamics miniapp. Laghos (LAGrangian High-Order Solver) is a miniapp that solves the time-dependent Euler equations of compressible gas dynamics in a moving Lagrangian frame using unstructured high-order finite element spatial discretization and explicit high-order time-stepping. Laghos is based on the discretization method described in the following article: V. Dobrev, Tz. Kolev and R. Rieben; High-order curvilinear finite element methods for Lagrangian hydrodynamics ; SIAM Journal on Scientific Computing, (34) 2012, pp. B606–B641.