2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/55183There have been many remarkable developments in our understanding of superstring theory in the past few years, a period that has been described as ``the second superstring revolution.'' Several of them are discussed here. The presentation is intended primarily for the benefit of nonexperts.16 pages, latex, two figures; minor corrections, references addedHigh Energy Physics - Theorytext