2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/78621We review several known categorification procedures, and introduce a functorial categorification of group extensions with applications to non-abelian group cohomology. Categorification of acyclic models and of topological spaces are briefly mentioned.AMS-LaTex, 10 pagesCategory TheoryGroup Theory18D10 (Primary) 18B40, 18G30 (Secondary)text