  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.
