Marc Rochkind: BSD is the new kind on the block. I don't think it came along until 1977 or so. Research UNIX I don't think picked up SCCS ever. SCCS first appeared in the PWB releases, if you don't count the earlier version in SNOBOL4 for the IBM mainframes. ===== Correct. We never needed no stinkin' revision control in Research. More fairly, early systems like SCCS were so cumbersome that a community that was fairly small, in which everyone talked to everyone, and in which there was no glaring need wasn't willing to adopt them. I remember trying SCCS for a few small personal projects back in 1979 or so (well before I moved to New Jersey), finding it just too clunky for the benefits it gave me, and giving up. Much later, I found RCS just as messy. One thing that really bugged me was those systems' inherent belief that you rarely want to keep a checked-out copy of something except while you're working on it. Another, harder to work around, is that in any nontrivial project there are often stages when I want to make changes of scope broader than a single file: factor common stuff out into a new file, merge things into a single file, rename files, etc. CVS was a big step forward, but not enough. Subversion was the first revision-control that didn't feel like a huge burden to me. None of which is to say that SCCS and RCS were useless; they were important pioneers, and for the big projects that originally spawned them I'm sure they were indispensible. But I can't imagine Ken or Dennis putting up with them for very long, and I'm glad I never had to. Norman Wilson Toronto ON