Each applet corresponds directly to one or more figures from Gerald Farin's book "Curves and Surfaces for CAGD - A Practical Guide", 5th ed., Academic Press, 2002.
In all applets listed below, green points are "draggable", i.e., they can be moved to another location by clicking them with the mouse and moving the mouse while keeping the mouse button pressed. Three-dimensional graphics can also be rotated by clicking anywhere else in the figure and dragging the mouse. Zooming is possible by holding down the SHIFT key and dragging vertically, rotation about an axis perpendicular to the screen is possible by holding down the SHIFT key and dragging horizontally. Other keys include the HOME key for getting back to the original configuration and "s" for stereo display. See the LiveGraphics3D homepage for more information about the employed applet.
The applets are in fact instances of just one applet (called LiveGraphics3D). I (Martin Kraus) produced the (parameterized) graphics for this applet with the help of the computer algebra system Mathematica. If you have any questions about these applets, please send me an e-mail.