I actually still use SCCS… sort of. I have some old code bases that are stored in SCCS. They’re actually Sun CodeManager/Teamware repositories, which used SCCS for file storage. I don’t actually update any files in SCCS; I use it only for browsing history. These old repos have been converted to git, but somehow I find it harder to trace through the history in the converted repo.

Instead, I use the open-sourced version of SCCS commands that the late Jörg Schilling ported to various OSes from the OpenSolaris/SVR4 source base. The guy was a real fan of SCCS. He even gave a conference talk on it once. Kind of retro computing, but for software instead of hardware.

https://news.ycombinator.com/item?id=28832682