New Spacetime-Supersymmetric Methods for the Superstring

In this talk, the new spacetime-supersymmetric description of the superstring is reviewed and some of its applications are described. These applications include the manifestly spacetime-supersymmetric calculation of scattering amplitudes, the construction of a super-Poincar\'e invariant open superstring field theory, and the beta-function calculation of low-energy equations of motion in superspace. Parts of this work have been done in collaboration with deBoer, van Nieuwenhuizen, Ro\v{c}ek, Sezgin, Skenderis, Stelle, and especially, Siegel and Vafa.