This is verging on COFF material, and I won't mind if someone moves the discussion thither: Clem Cole: As a satisfied user of SCCS (and later Bitkeeper), it's still my preferred choice. ==== I have to admit SCCS is one of the many pieces of software I tried for a week or two > 40 years ago and abandoned because I couldn't stand it. I don't think I ever tried RCS, because I could see it didn't what I saw as the underlying problems. CVS likewise. Subversion was the earliest version-control system that felt usable to me. What bugged me so much? The earlier systems were focussed entirely (or for CVS, almost entirely) on individual files. There was no way to link changes that affected more than one file: -- SCCS and RCS don't (so far as I can tell) understand any relation between files at all. When I'm working on a real project of any size, there is almost always more than one file, and there are often changes that affect multiple files at once: if an interface changes, the changes to definitions and uses really all should be a single commit, logged in one go and reversible as a single coordinated operation; if I refactor code, moving it between files and perhaps adding files or removing them, likewise. It is possible to check in a bunch of files at once and reuse the log message, but I couldn't find a way to make it a true coordinated single commit; and neither SCCS nor RCS has a way I could find to record, as a structured commit, that files are added or removed from a directory or directory tree. -- CVS can track adds and deletes and can bundle changes into a single commit on the command line, but the changes are still stored individually per file. -- None of the systems even tries to track file renames, something I also do occasionally as programs and especially documentation evolves. It wasn't until I discovered Subversion that I started using version control regularly in my own work. Ironically, a few years after I began using svn for myself, I ended up working in places that had great compost heaps of RCS and CVS. This would have made sense in the 1990s, but it was in the 2010s, and continues in the 2020s. I now use hg for my personal work, and have been attempting to drag my workplace into using git if only so new hires don't have to learn clumsy outdated stuff just to do their jobs. I expect to retire (not for this reason) before I really succeed, though. Norman Wilson Toronto ON