GNU RCS is available at https://www.gnu.org/software/rcs/
This page is mostly of historical interest, but contains some content that is not part of the GNU distribution and may not be available elsewhere.
The source distribution is intended primarily for UNIX systems. Some people have been successful in porting it to other systems as well.
The latest PC (OS/2 DOS Win95 NT) binary version is available as
three ZIP files. They are rcs57pc1.zip (1.2MB), rcs57pc2.zip (0.9MB) and rcs57pc3.zip (0.9MB).
They contain everything you should need to use RCS on a PC.
If you want to try to compile RCS on a PC, you will need
the supplementary
source file (41K). This contains diffs relative to RCS
5.7 and diffutils 2.7.1 sources.
In July 2020 John Kelly provided a
patch (1.5K) that he used to build
RCS 5.7 on DOS. It corrects a bug with -o1.1 (delete all
revisions) and provides a makefile that works on DOS (shorter
command line lengths in real DOS vs OS/2).
If you have problems fetching the files with HTTP, you can use FTP to fetch the necessary files from the RCS FTP site.
UNIX style man(ual) pages are included in the distributions. There is some additional documentation available on-line. The first is a modified version of the paper that appeared in Software Practices & Experience, July 1985. It is available in PostScript (138K) or *roff (55K). If you want to *roff format, but don't have the pic preprocessor, you need to the pre-piced (63K) version.
The second document is a one-page summary describing the functions of RCS. It is available in PostScript (9K) or *roff (3K).
The third document is a book written by Brian O'Donavan while at Digital Equipment Corporation. It was never published, but he gave it to Purdue to see if there was any interest from RCS users. It is a compressed tar file (248K)
O'Reilly & Associates, Inc. also published Applying RCS and SCCS by Don Bolinger and Tan Bronson.
Please see the FAQ as a first pass. If this does not answer your question, you can join the GNU RCS help mailing list for general help with RCS, or the GNU RCS bug report list for bug reports.
All contributed software is made available as-is, with no warranty by either the contributors or the RCS maintainers.
CVS is an open source version control system layered on top of RCS, designed to manage entire software projects.
Applied Computer Sciences offers their /BriefCase 3 Toolkit for free under the GPL, and promotes it as a true client/server solution for UNIX, providing better project management than CVS.
PRCS is supposed to be a much simpler CVS-like tool.
BitKeeper is a fully distributed source management system from BitMover, Inc. It is based on their version of SCCS and is file format compatible with AT&T SCCS.