2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/55145N=2 heterotic strings may provide a window into the physics of M-theory radically different than that found via the other supersymmetric string theories. In addition to their supersymmetric structure, these strings carry a four-dimensional self-dual structure, and appear to be completely integrable systems with a stringy density of states. These lectures give an overview of N=2 heterotic strings, as well as a brief discussion of possible applications of both ordinary and heterotic N=2 strings to D-branes and matrix theory.29 pages, latex; lectures at the Cargese summer school Strings, Branes, and Dualities, June 1997High Energy Physics - Theorytext