Twistor string as tensionless superstring

We give a brief review of the twistor string approach to supersymmetric Yang-Mills theories with an emphasis on the different formulations of (super)string models in supertwistor space and their superspace form. We discuss the classical equivalence among the Siegel closed twistor string and the Lorentz harmonics formulation of the (N=4) tensionless superstring, and notice the possible relation of the twistor string to the D=10 Green-Schwarz superstring action, as well as to models in the enlarged, tensorial superspaces that are relevant in higher spin theories.Comment: plain latex, 9 pages. Talk delivered at the Workshop of the RTN network 'Constituents, fundamental forces and Symmetries of the Universe', Napoli October 9-13, 2006, to appear in Fortschritte der Physi