This small program computes (a superset of) all possible faithful actions of a cyclic group on a smooth algebraic curve (Riemann surface) of genus g, given the information on a part of the ramification.
In other words, the program computes all possible cyclic subgroups of Aut(F) for some curve F of genus g. The actual possibilities may be fewer than the ones computed, because the program implements some necessary conditions that are not sufficient.
See [1] for a presentation of the program with some properties.