  We briefly review results on two-dimensional supersymmetric quantum field
theories that exhibit factorizable particle scattering. Our particular focus is
on a series of $N\!=\!1$ supersymmetric theories, for which exact $S$-matrices
have been obtained. A Thermodynamic Bethe Ansatz (TBA) analysis for these
theories has confirmed the validity of the proposed $S$-matrices and has
pointed at an interesting `folding' relation with a series of $N\!=\!2$
supersymmetric theories.
