Looking for a program



Dear All,
 I am looking for a program that:
 1- Would work under UNIX (in particular Linux & Irix),
 2- Could be ran using scripts i.e. in a non-graphical way,
 3- Would allow to (i) load a structure, (ii) modify/control its orientation
 (axis x, y, and z), and (iii) save the new Cartesian coordinate set defined by
 the new orientation, and if possible
 4- would be freely distributed for all users...
 Thanks, Regards, Francois