Coming from RCS, CVS, SVN to Git, git is a game changer - yes everyone knows that.
But what was astonishing me most was the version system build into the VMS OS file system.
But what was astonishing me most was the version system build into the VMS OS file system.
That was more of "versioning" than "version control" system. It simply automated the sequential numbering of the saved instances of a file. The versions were not deltas, just normal files, the version number being part of file specification:
name.ext;ver
As much as one can do with versions was diff, purge and file operations, basically, no change annotation or higher level grouping. But being files, the versions allowed to see the what-who-when changed. No why. Still this probably was convenient in some use-cases and as an immediate file backup.
As for the real version control system on OpenVMS, one of such was called CMS, part of DECset suite. I believe it was of exclusive-check-out/check-in kind, similar to how it's done with, say, CVS, but absolutely not like CVS otherwise. For example, there was no support for directories in the repository.
I guess these days it may be possible to run Git on OpenVMS too.
File versioning is also part of pathnames in Common Lisp, although it (the versioning, not Common Lisp) is really a fossil at this point.