The image above (water) is from Mark Gerstein's Macromolecular Geometry website located at: http://bioinfo.mbb.yale.edu/geometry/gallery.html

The applet used here is presented in the JOMA article Lite Applets by F. Wattenberg, B. Stewart, and  S. Alejandre. The authors encourage others to use this applet, which may be downloaded at:
http://www.joma.org/vol2/articles/wattenberg/JOMA_article/wattenberg1.html

Here is a text source for this webpage (LiteApplet1.html): LiteApplet1.txt