This demo includes two graphical display windows.

The window "Curve: X(t)" displays the curve X(t), the point X(t0), the unit tangent and principal normal vectors T(t0) and P(t0) with their tails at X(t0), and the osculating plane at X(t0).

The window "T(t) and P(t)" displays the unit tangent and principal normal vectors T(t0) and P(t0), the unit sphere on which their heads are constrained to lie, and the osculating plane from the "Curve: X(t)" window, going through the origin instead of X(t0).

You can change t0 and X(t) in the control window. The control window includes a list of functions that you can use for X(t), along with parameters used to define those functions.