This is Debian's prepackaged version of the GNU Project's Revision Control System (RCS) utilities. These utilities allow you to keep multiple revisions of one or more files in a very compact manner. RCS is similar to, and in most respects better than, the non-free Source Code Control System (SCCS). This package was assembled by Sven Rudolph from the GNU sources available from prep.ai.mit.edu (and its numerous mirrors) as /pub/gnu/rcs-5.7.tar.gz. It is currently maintained by Romain Francoise . The upstream URL is: http://www.gnu.org/software/rcs/ Copyright (C) 2010-2012 Thien-Thi Nguyen Copyright (C) 1990-1995 Paul Eggert Copyright (C) 1982,1988,1989 Walter F. Tichy, Purdue CS RCS is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. RCS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. The RCS manual is distributed under the GNU Free Documentation License version 1.3 or later, with no invariant Sections, with no front-cover texts, and with no back-cover texts. The RCS source distribution also includes several gnulib modules, which are also licensed under the GPL version 3 or later, and are: Copyright 1990-2012 Free Software Foundation, Inc. On Debian systems, the complete text of the GNU General Public License can be found in `/usr/share/common-licenses/GPL-3'. The complete text of the GNU Free Documentation License can be found in `/usr/share/common-licenses/GFDL-1.3'.