Towards higher-N superextensions of Born-Infeld theory
  We give a brief account of supersymmetric Born-Infeld theories with extended supersymmetry, including those with partially broken supersymmetry. Some latest developments in this area are presented. One of them is N=3 supersymmetric Born-Infeld theory which admits a natural off-shell formulation in N=3 harmonic superspace. 
E. Ivanov