William Fairbank has been a dear friend and an enthusiastic colleague who has given us with his vitality and originality a marvelous example of how to broaden the frontier of science and knowledge. Every encounter with him gave us an injection of enthusiasm and some new physical insight, every visit to his laboratory a sensation of exploring the fundamentals of gravitation through the most original use of basic physics, and every encounter with his research group an opportunity to discuss some of our most recent results in theoretical research with an outstanding group of experimentalists.

These meetings have been conceived with the aim of keeping alive the "Bill Fair-bank ₅p~~t~ and to extend it to a larger and larger number of scientists.

The success of the meeting could not have been achieved without the dedication of the organizing committee: B. Bertotti, I. Ciufolini, G. Coyne, T. Damour, M. Dobrowolny, J. Ehlers, C.W.F. Everitt, L.Z. Fang, R.W. Hellings, R. Jantzen, S. Leschiutta, Y. Ne'eman, K. Nordtvedt, U. Ponzi, and R. Ruflini, nor without the great help of the secretaries of the meeting: Armida Berti, Cesare Corsetti, and Giulia Tracia and the crucial financial assistance of the sponsors of the meeting: the Italian Space Agency (ASI), the European Space Agency (ESA), the International Center for Relativistic Astrophysics (ICRA), the Vatican Observatory, Stanford University, and the University of Rome "La Sapienza".

We are particularly grateful to His Holiness Pope John Paul II for his audience at Castel Gandolfo for the participants of the meeting.

L.Z. Fang and R. Ruflini, Editors of the Series