These Proceedings contain selected original papers by the speakers invited to the Seminar on Deformations, organized in 1988/92 by Julian Lawrynowicz (L6di), whose most fruitful parts took place in 1988 in E6di, Paris and Mexico City (Profs. J. Adem, F. de1. Castillo Alvarado, G. Contreras Puente, R.M. Porter, E. Ramirez de Arellano - Mexico, D.F.; Prof. B. Gaveau - Paris; Profs. J. Lawrynowicz, J. Rembielinski, L. Wojtczak - Mdi et all.), in 1990 in -Mdi, Tokyo and Sapporo (Profs. S. Koshi - Sapporo, O. Suzuki - Tokyo, J. Lawrynowicz - L6di et all.), in 1991 in t6diand Rome (Profs. S. Marchiafava, F. Succi- Rome, J. Lawrynowicz, 1. Wojtczak - l.6di et all.), and in 1992 in E6di and M alinka - Mazurian Lakeland, Poland (Profs. C. Surry - Saint Etienne, J. Lawrynowicz, J. Rembielinski, 1. Wojtczak - L6di et all.). The meetings of the Seminar and the Proceedings were supported by the Polish state Committee for Scientific Research (KBN) and the -L6di Society of Sciences and Arts (LTN).