To see all the wonderful java applets of IES in Japan  go to http://www.ies.co.jp/math/java/  You can now see Don's  ideas in four Java applets at IES-

1. one is "Iterating I^(I^(I^I)).." from ch. 11- a WOW!!,at http://www.ies.co.jp/math/java/comp/itoi/itoi.html

2. "The six trig functions"-all at one time! at http://www.ies.co.jp/math/java/trig/sixtrigfn/sixtrigfn.html  The Japanese version of the above at http://www.ies.co.jp/LoveMath/kihonjikou/sixtrigfn-j/sixtrigfn-j.html The version above in Denmark at  http://www.itc.fa.dk/software/ies-math/trigonometri/applets/sixtrigfn/sixtrigfn.html

3. From Don's book "Changing Shapes With Matrices" on his website!

4. See the IES version of Maggie's difference of two cubes at http://www.ies.co.jp/math/java/misc/magbox/Magbox1.html

See the Nautilus shell at the IES Java applet of the shell at http://www.ies.co.jp/math/java/misc/oum/oum.html

See many applets for Pythagorean Theorem at http://www.ies.co.jp/math/java/geo/pythagoras.html

Xah Lee's work on the Equiangular Spiral (the Nautilus shell - Don's favorite! :-)  )at http://xahlee.org/SpecialPlaneCurves_dir/EquiangularSpiral_dir/equiangularSpiral.html 

Ron Knott's fine work on Fibonacci numbers and the golden mean

The best MathED site on the www! The Math Forum now at Drexel University.

"Cut-The-Knot" site by Alexander Bogomolny has some very fine mathematics, games and puzzles