This presentation will review some recent and key features in singlet-singlet and triplet-triplet through space energy transfer in cofacial bisporphyrines and related mixed macrocycles, whether the two chromophores are held together by covalently bonded rigid or "semi-rigid" spacers. Topics such as the Förster and Dexter mechanims, comparison with through space vs through bond, relative orientation of the donor and acceptor chromophore, distance dependance, and exciton behavior will be discussed.