The Chemshell computational chemistry environment (http://www.chemshell.org) offers an interface to many well known force field software (CHARMM, GROMOS, GULP,...). The program supports several geometry optimization algorithms; a molecular dynamics driver for , and ensembles; Monte Carlo; and many other utilities.
The Chemshell Manual can be found at the following website:
Instructions on the use of Molpro are available therein. Also concerning the Chemshell environment, a free Graphical User Interface (GUI) has been released. The CCP1GUI facilitates the input for hybrid calculations, allows visualisation of molecular structures and includes molecule editing tools: