The Virasoro conjecture for Gromov-Witten invariants
  The Virasoro conjecture is a conjectured sequence of relations among the descendent Gromov-Witten invariants of a smooth projective variety in all genera; the only varieties for which it is known to hold are a point (Kontsevich) and Calabi-Yau threefolds (S. Katz). We review the statement of the conjecture and its proof in genus 0, following Eguchi, Hori and Xiong.   This version incorporates many changes and improvements compared with the first, and a small number of misprints from the second. It will appear in the AMS volume "Hirzebruch 70", edited by P. Pragacz et al. 
Ezra Getzler (Northwestern)