Preface. 1. Introduction. 2. String Phenomenology in the Classical Limit. 3. More and more Compactifications. 4. Quantum Effects and Perturbative Supersymmetry Breaking. 5. Non-perturbative Supersymmetry Breaking. 6. Prospects. 7. References. 8. Papers: Outlines of a Phenomenology. Contributors: J.D. Breit, P. Candelas, G.T. Horowitz, B.A. Ovrut, G.C. Segrè, A. Sen, E. Witten. Features of the Low-energy Theory. Contributors: M. Dine, M.D. Freeman, M.T. Grisaru, D.J. Gross, D. Nemeschansky, C.N. Pope, N. Seiberg, A. Sen, A.E.M. van der Ven, X.G. Wen, E. Witten, D. Zanon. Solvable Conformal Field Theories. Contributors: L. Dixon, D. Friedan, J.A. Harvey, E. Martinec, M. Mueller, K.S. Narain, M.H. Sarmadi, S. Shenker, C. Vafa, E. Witten. Quantum Corrections to Classical Solutions. Contributors: M. Dine, E. Martinec, N. Seiberg and E. Witten. Beyond Perturbation Theory. Contributors: M. Dine, J. Derendinger, L.E. Ibáñez, H.P. Nilles, R. Rohm, N. Seiberg, E. Witten.