3D-XplorMath is a freely available Mathematical Visualization program. The program presents itself as series of galleries of different categories of interesting mathematical objects, ranging from planar and space curves to polyhedra and surfaces to ordinary and partial differential equations, and fractals. The 3D-Xplore Math Consortium offers these images here and provides documentation with suggestions for how to explore further.

— *Richard Palais (University of California at Irvine)*

This striking object is an example of a surface in 3-space whose intrinsic geometry is the hyperbolic geometry of Bolyai and Lobachevsky. Such surfaces are in one-to-one correspondence with the solutions of a certain non-linear wave-equation (the so-called Sine-Gordon Equation, or SGE) that also arises in high-energy physics. SGE is an equation of soliton type and the Breather surface corresponds to a time-periodic 2-soliton solution.

In 1890 David Hilbert published a construction of a continuous curve whose image completely fills a square, which was a significant contribution to the understanding of continuity. Although it might be considered to be a pathological example, today, Hilbert's curve has become well-known for a very different reason---every computer science student learns about it because the algorithm has proved useful in image compression. (Adapted from "About Hilbert's Square Filling Curve" by Hermann Karcher.)

A striking aspect of this image is its self-similarity: Parts of the set look very similar to larger parts of the set, or to the entire set itself. The boundary of the Mandelbrot Set is an example of a fractal, a name derived from the fact that the dimensions of such sets need not be integers like two or three, but can be fractions like 4/3.

The Hopf map maps the unit sphere in four-dimensional space to the unit sphere in three-dimensional space. The four tori linked in this image are made up of fibers, or pre-images, of the Hopf map. In this visualization, each fiber has a constant color and the color varies with the distance of the fibers. Any two of the four tori are linked, as are any pair of fibers on a given torus. (Adapted from "Hopf Fibration and Clifford Translation of the 3-Sphere," by Hermann Karcher.)