Higher Dimensional
5D Cube, Hyperspace Structures: Exploring the Fourth Dimens, Mark Newbold's Java Stuff, Polyobjects: Math's Final Project, Regular 4d Polytope Foldouts, Uniform Polychora, Uniform Polytopes in Four Dimensions
Polyhedra
A Ride Through the World of Polyhedra, Alexander's Polyhedra, Circumnavigating a Cube and a Tetrahedron, Fr. Magnus Wenninger OSB, Gallery of Polyhedra, handsonmath.com, Harold Scott MacDonald Coxeter, Juno's World, Martin's Pretty Polyhedra, Mathematica Graphics Gallery
Software
Hypercube Downloads by Rudy Rucker and Farideh Dor, PEEK, POLY, Polyhedra 2001, Polyhedra by Bob, PPL: The Parma Polyhedra Library, Stella: Polyhedron Navigator, The Many Faces of Polyhedrons
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.
Numericana - Polyhedra & Polytopes
Enumeration, cartesian coordinates of vertices, naming, and counting the shapes.
Polygons, Polyhedra, Polytopes
Regular, rectified, and truncated polytopes with normal and hidden-detail-removed projections. Images, animations, and links.
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.
Regular Polytopes
Derivation of volume equations for regular polygons, polyhedra, and polytopes, with images.
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.
The Geometry Junkyard
Comprehensive list of links to sites on geometric properties of the shapes.
The Mathematical Atlas - Polytopes and Polyhedra
Collection of discussions regarding volume, vertices, dissection, g-holed tori, and other subjects.
Zome Edu
An educational toy and industrial tool to teach geometry and model complex and simple shapes, from cubes to Fullerenes.