You can find here all the external python package that are currently supported in ePMV/PMV. An extension is active / available for ePMV if its in the $MGLROOT/MGLToolsPkgs directory or if its define in the $MGLROOT/MGLToolsPkgs/Pmv/hostappInterface/extension/liste.txt file as follow. Note that an extension will work only for compatible python version. For instance, PyRosetta is build using python2.5 thus you will need a python2.5 environment such as blender.

   extname:pathtoextension
   modeller:/Library/modeller-9v8/modlib/
   PyRosetta:/Library/MGLTools/1.5.6/MGLToolsPckgs/PyRosetta
   ...