Our local group has developed a free JAVA applet that helps users to
study spatial geometry in a dynamic and interactive way. Using it, the
user can rotate, zoom out, zoom in and translate a plethora of
polyhedra. Moreover, the program is able to compute topological and
geometrical duals of each polyhedron. Geometrical operations include
unfolding, plane sections, truncation and stellation.
http://www.uff.br/cdme/pdp/pdp-html/pdp-en.html
Suggestions are welcome!
Thanks in advance, Humberto.