To see and test the applets you need Java 7 32-bit and Java 3D (for some applets) installed.
In case you use Mozilla Firefox-it must be 32-bit. 
And you must set in Java Control Panel  the  Security Level to Medium.


Curves
3D Bezier curve
User guide

Cross Plot
User guide

Hodograph

Degree elevation 
User guide

2D polar and 3D polar

C1 quadratic spline

C2 cubic spline (3D)

C2 cubic  interpolational spline

C1 cubic  interpolational splinewith Bessel tangents
 
Catmull-Rom spline

Cubic spline function

Chaikin algorithm (corner cutting)
User guide

4-point subdivision
User guide

Surfaces
Tensor product Bezier surfaces

Triangular Bezier surfaces
  
LoopButterflyKobbelt
User guide

Sqrt2-subdivision

4-8-subdivision