Seiberg-Witten Prepotential from Instanton Counting

Direct evaluation of the Seiberg-Witten prepotential is accomplished following the localization programme suggested in [1].Our results agree with all low-instanton calculations available in the literature.We present a two-parameter generalization of the Seiberg-Witten prepotential, which is rather natural from the M-theory/five dimensional perspective, and conjecture its relation to the tau-functions of KP/Toda hierarchy.