This demo includes three graphical display windows.

The window "Curve: X(t)" displays the curve X(t), the point X(t_{0}),
and the unit tangent,
unit normal, and unit binormal vectors T(t_{0}),
P(t_{0}), and B(t_{0}).

The window "Unit Tangent (T), Unit Normal (P), and Unit Binormal (B)"
displays the unit tangent,
unit normal, and unit binormal vectors T(t_{0}),
P(t_{0}), and B(t_{0}) with their tails at the origin,
along with the unit sphere on which their heads are constrained to lie,
and B'(t_{0}), the derivative of B(t) evaluated at t_{0},
with its tail starting at the head of B(t_{0}).

The window "Torsion(t)" graphs the torsion of X(t).

You can change t_{0} 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.