This collection of 18 research papers, dedicated to Pierre Lelong, describes the state of the art on representative problems of complex analysis and geometry. The book opens with an exposition of the achievements of Pierre Lelong on plurisubharmonic functions, closed positive currents, and their further study by other mathematicians. Moreover, a list of eleven open problems is given. All other contributions contain new results related, for example, to the following items: - Capacities, product of positive currents, L2 extension theorems, Bergman kernels and metrics, new properties of convex...