Periodic gravity-capillary waves propagating at a constant velocity at the
surface of a fluid of infinite depth are considered. The surface tension is
assumed to vary along the free surface. A numerical procedure is presented
to solve the problem with an arbitrary distribution of surface tension on
the free surface. It is found that there are many different families of sol
utions. These solutions generalize the classical theory of gravity-capillar
y waves with constant surface tension. An asymptotic solution is presented
for a particular distribution of variable surface tension.