Zome Edu  
   An educational toy and industrial tool to teach geometry and model complex and simple shapes, from cubes to Fullerenes.
   http://www.zometool.com/edu/

The Mathematical Atlas - Polytopes and Polyhedra  
   Collection of discussions regarding volume, vertices, dissection, g-holed tori, and other subjects.
   http://www.math.niu.edu/~rusin/known-math/index/52BXX.html

The Geometry Junkyard  
   Comprehensive list of links to sites on geometric properties of the shapes.
   http://www.ics.uci.edu/~eppstein/junkyard/polytope.html

Sliceform models by John Sharp  
   Three-dimensional objects constructed by slotting together a series of planar cross sections made from card. Downloadable templates in PDF, PS and Word formats.
   http://www.mathsyear2000.org/resources/slice/

Polyhedra, Platonic Solids, Polytopes  
   Definitions, pictures, templates, and coordinates of the regular 3d and 4d polytopes. Also includes waterman polyhedra, polar and star spheres, and the time star.
   http://astronomy.swin.edu.au/~pbourke/polyhedra/

The Charged Particles Model  
   Polytopes and optimal packing of p points in n dimensional spheres. Contains a java applet based on a model which allows for generation of multidimensional regular and semi-regular polytopes.
   http://presh.com/hovinga

Numericana - Polyhedra & Polytopes  
   Enumeration, cartesian coordinates of vertices, naming, and counting the shapes.
   http://home.att.net/~numericana/answer/polyhedra.htm

Guy's Polyhedra Pages  
   Vertex figures, filling, faceting diagrams, stellation, defining polytopes through generators, trimethoric and trisynaptic polyhedra, space-filling polyhedra, lost stellations of the icosahedron, and links.
   http://www.queenhill.demon.co.uk/polyhedra/

Regular Polytopes  
   Derivation of volume equations for regular polygons, polyhedra, and polytopes, with images.
   http://www.math.rutgers.edu/~erowland/polygons.html