2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/126764Complementing the presentations, at this conference, of the first experimental evidence for $D$ mixing found at BaBar and Belle, I discuss the theoretical status of $D$ mixing.Quasi-Impromptu Talk given at XLIInd Rencontres de Moriond, Electroweak Interactions and Unified Theories, La Thuile, Italy, March 2007; typos removed; acknowledgements addedHigh Energy Physics - Phenomenologytext