I use PVCS under DOS (actually under the MKS Toolkit Korn shell under DOS).
It is also usable under Windows, but it is not free.  Mine is an old
version, and now it is pretty expensive.  If you like RCS, MKS has Source
Integrity which is really their RCS product with a new name.  I have not
used it, but MKS makes some pretty good stuff and superb support if you pay
for the service contract.

>But seriously folks ...
>
>Does anybody here use revision control software.  I have been using RCS,
>one of the GNU utilities, for a long time and would not be without it or
>smemthing equivlaent.  Unfortunately it is a DOS based, command line
>driven set of programs and evidently too complex for the younger members
>of our company to grasp.  Did I mention that it is a free program.
>
>One of my sons (A C programmer) works at a different where they use
>something from Micro$oft that seems to the trick for them.  I have
>also heard of PVCS but don't know anything about it.
>
>Perhaps a few people would be willing to share their experiences.
>