Introduction to Dieudonné modules and supersingular abelian varieties revisited

In this Note we present an expository account for \dieu modules and revisit supersingular abelian varieties. We give a simple proof of the uniqueness of products of two or more supersingular elliptic curves (a theorem due to Deligne, Ogus and Shioda), and of Oort's theorem for superspecial abelian varieties.