2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/69665This semi-expository paper surveys results concerning three classes of orthogonal polynomials: in one non-hermitian variable, in several isometric non-commuting variables, and in several hermitian non-commuting variables. The emphasis is on some dilation theoretic techniques that are also described in some details.29 pages, 4 figuresFunctional Analysistext