I have not used sccs nor rcs for version control as such, but I have used them a little. The BSD archives published by Kirk McKusick include the source reposit

I have not used sccs nor rcs for version control as such, but I have used them a little. The BSD archives published by Kirk McKusick include the source repository in sccs, so I have used sccs a little to drill down into nuggets of history there. In a former job I inherited some sccs repositories which I converted to git. (I believe in preserving history) https://dotat.at/@/2014-11-27-uplift-from-sccs-to-git.html https://dotat.at/@/2014-11-27-uplift-from-sccs-to-git.html https://dotat.at/@/2016-07-19-uplift-from-sccs-to-git-again.html https://dotat.at/@/2016-07-19-uplift-from-sccs-to-git-again.... (sadly the links to the scripts are broken; I wonder if I can get permission to republish them…) More weirdly we had an ancient and janky terminal-based user interface to allow colleagues to edit configuration files in a controlled manner. It avoided concurrency problems by using rcs under the cover to implement locking.