Drawing Bézier curves with JavaScript and VML (for IE only)
A progressive lesson:
Simplest case (changing the y coordinate of one endpoint)
Generalization (identifying the two end points)
Adding behavior (an earthworm in a cyclone)
Grouping things and moving them together as a group
Attaching two bézier curves together, smoothly (let them share a point, and let the adjacent control points be collinear with the shared point)
Fancier things:
Eeliness (letting points on the curve follow one another, sort of)
a simpler version (my kids like it better)
and a bézier tree
See copyright notice.