Although this Seventh Edition no longer bears their byline, Ken Thomp‐
son and Dennis Ritchie remain the fathers and preceptors of the UNIX
time-sharing system. Many of the improvements here described bear
their mark. Among many, many other people who have contributed to the
further flowering of UNIX, we wish especially to acknowledge the con‐
tributions of A. V. Aho, S. R. Bourne, L. L. Cherry, G. L. Chesson, S.
I. Feldman, C. B. Haley, R. C. Haight, S. C. Johnson, M. E. Lesk, T. L.
Lyon, L. E. McMahon, R. Morris, R. Muha, D. A. Nowitz, L. Wehr, and P.
J. Weinberger. We appreciate also the effective advice and criticism
of T. A. Dolotta, A. G. Fraser, J. F. Maranzano, and J. R. Mashey; and
we remember the important work of the late Joseph F. Ossanna.
B. W. Kernighan
M. D. McIlroy