High school teacher Glenn Elert wrote the original edition of the Chaos Hypertextbook for his M.S. degree in secondary science education at Teachers College, Columbia University. After graduation, Elert put the hypertext on the Internet for the benefit of people interested in mathematics, chaos, non-linear dynamics, and fractals. While the hypertext does require some mathematical knowledge, it is geared towards a wide audience. The hypertext addresses a variety of interesting topics including one-dimensional iterated maps; fractal construction; applications and definitions of dimension; and a comparison of non-linear and linear dynamics. The site also offers information about print, software, and Internet resources as well as a fun Eye Candy section. Site visitors can also link to other hypertexts by Elert including The Physics Factbook (an encyclopedia of scientific essays written by high school students), and the Physics Hypertextbook, which is currently under construction.