Hyperspace Travel
- Images and animations of a couple of four-dimensional objects, along with the math and source code used to produce them. Links to software to interactively visualize four-dimensional objects.
- http://www.hyperspace-travel.de

Four-Space Visualization of 4D Objects
- Mathematical and computer programming oriented approach. Discusses wireframe rendering and ray-tracing.
- http://stevehollasch.com/thesis/

HyperCube by Harmen
- A short introduction to the fourth dimension, plus a hypercube java applet game.
- http://www1.tip.nl/~t515027/hypercube.html

Hyper Dimensia
- Tutorial which aims to give readers an understanding of the fourth dimension by having them use a java applet to rotate a cube and a hypercube to see multiple views of the shapes at once.
- http://www.hyperdimensia.com/

Fourth Dimension: Tetraspace
- A discussion of rotation, levitation, wheels, and bodies of water. Classification of "rotatopes" (cubes, spheres, and cylinders), and a Java applet to visualize projections and intersections of the shapes. Includes book reviews, a glossary, link
- http://tetraspace.alkaline.org