All of these web pages were generated by typing things into Mathematica and then telling it to save as HTML. All I had to do then was to copy it to my web directory. There was no html editing required. The only exception was in the animations at the bottom of the page. Mathematica doesn't automatically generate the animations for your web pages. It is fairly simple to do but you have to edit your pages a bit to get animations on the web. (To make changes, I changed the Mathematica document and saved it out again and recopied it to the web.)
This shows the "beating"of two sin waves:
This shows a tangent line moving along a sine curve:
This shows a Taylor series being fit to a sine curve:
