  This paper gives a brief contact-geometric account of the Pontryagin maximum
principle. We show that key notions in the Pontryagin maximum principle---such
as the separating hyperplanes, costate, necessary condition, and
normal/abnormal minimizers---have natural contact-geometric interpretations. We
then exploit the contact-geometric formulation to give a simple derivation of
the transversality condition for optimal control with terminal cost.
