Version control was done using the features of the VMS filesystem. I believe that HP MPE had something like that also, but I may have blocked it out.
Around about late '93 early '94 they hauled the HP terminal away and slapped a SparcClassic (or IPX? IPC?) in it's place. I was tapped to be part of the team to start migrating what we could off the VMS system to run on Solaris. So, I had to learn this odd language called See, Sea, umm 'C'?
A whole need set of manuals. A month's salary on books. Then another few books on how to keep that damn Sparc running with any consistency.
Then had to setup CVS. Sure, why not run the CVS server on my workstation!
By the end of '95 I was working mainly on maintaining the Solaris (and soon HP/UX and AIX) boxes then programming.
I still miss writing code with EDT on VMS and hacking away on fun things with FORTRAN. You know, like actually writing CGIs in FORTRAN. But that is another story.