Yes, but what is VISTA made of?
So at the MUMPS level, VISTA is made of two kinds of software elements, routines and globals. Routines are readily version-controlled and managed (in theory) using industry-standard tools, but globals are not. Globals need to be flattened and exported in some way that focuses on the database files we are storing in those globals.
As we're going to see, this second "half" of the problem (globals, as opposed to routines) is really a lot more than half the problem.