HYDRAD (HYDrodynamics and RADiation) computes solutions to field-aligned hydrodynamic equations in coronal loops. The code models a broad variety of phenomena, including multi-species plasma confined to full-length, magnetic flux tubes of arbitrary geometrical and cross-section variation in the field-aligned direction; solar flares driven by non-thermal electrons3 and Alfven waves4, and the non-thermal equilibrium response of the chromosphere; and coronal rain formed by condensations in thermal non-equilibrium where the adaptive grid is required to fully resolve and track multiple steep transition regions. HYDRAD also models ultracold, strongly coupled laboratory plasmas composed of weakly-ionized strontium. The code, written in C++, is modular in its structure; new capabilities can be added in a relatively straightforward way and handled robustly by the numerical scheme. HYDRAD is also intended to be fairly undemanding of computational resources, though its needs do depend strongly on the particular nature of each model run.