VMD is a molecular visualization software for displaying, animating, and analyzing large biomolecular systems using 3-D graphics and built-in scripting. VMD supports computers running MacOS X, Unix, or Windows, is distributed free of charge, and includes source code.

VMD can be used to display the results of HOLE calculations. HOLE calculates pore dimensions of the holes through molecular structures of ion channels. This is one of many examples of how third party packages can make use of the visualization capabilties of VMD.

VMD provides a wide variety of methods for rendering and coloring a molecule: simple points and lines, CPK spheres and cylinders, licorice bonds, backbone tubes and ribbons, cartoon drawings, and others.
VMD can be used to animate and analyze the trajectory of a molecular dynamics (MD) simulation. In particular, VMD can act as a graphical front end for an external MD software by displaying and animating a molecule undergoing simulation on a remote computer.

The license of this software is Freeware, you can free download and free use this 3d graphic software.