For those who need to parametrize new ligands, there is a new alternative VMD pluggin, named Paratool, to do so. It works for both AMBER and CHARMM, but has been specially designed for the latter one.
An excellent webpage with e-links to different programs / packages that have been specially designed for theoretical chemistry (QM, docking, chemoinformatics, crystallography...) classified as open-source, freeware, commercial or free for academics.
Hihgly recommended if you are looking for a program for doing something but your budget is limited
Here, a brief depiction on how to run docking with rbdock program: