Contents: Introduction to Quantum Field Theory, Path Integrals and String (B Hatfield); From Polyakov to Moduli (J Polchinski); Geometry of Quantum Strings (E D'Hoker & D H Phong); BRST Quantization and BRST Cohomology (N Marcus & A Sagnotti); Analytic Structure of Two-Dimensional Quantum Field Theories (P Nelson); Geometrical Meaning of Currents in String Theory (O Alvarez & P Windey); String Field Theory and the Geometry of Moduli Space (S Giddings); String Theory Without a Background Spacetime Geometry (G Horowitz); Holomorphic Curves on Manifolds of SU(3) Holonomy (E Witten); Vertex Operator Calculus (I Frenkel et al.); On Determinant Line Bundles (D Freed); h-Invariant and the Index (I Singer); Action Principles and Global Geometry (G Zuckerman)