The images were drawn on a Macintosh running OSX using MacMegaPov 0.7, which is an unofficial compiled version of POV-Ray. In particular, this version includes an isosurface patch by R. Suzuki which is the key to constructing the images portrayed here. POV-Ray (The Persistence of Vision Raytracer) is a high-quality, totally free tool for creating stunning three-dimensional graphics. It is available in official versions for Windows 95/98/NT, DOS, the Macintosh, i86 Linux, SunOS, and Amiga. The source code is available for those wanting to do their own ports. MegaPov (formerly UVPov, SuperPatch, and MultiPatch) is a cooperative work by members of the POV-Ray community with versions for Macintosh, Linux, MS-DOS, and Windows versions available.
The "dot-density" image files (using the Jmol applet view) were calculated on a Macintosh running OSX using the totally brilliant HyperCard running in classic mode.