> [...] It looks like the way the software is currently stored rules out
> using backup to compare the files.

   Huh?  I'm lost.  Can you explain this?  _What_, exactly, about "the
way the software is currently stored rules out using backup to compare
the files"?

> The solutions are therefore to maintain a production software tree and
> compare use DIFF to compare to the development tree or to backup the
> most recent version of each file when a release is finalised.

   As shown earlier, BACKUP /COMPARE works just fine for me in this
role, to the extent that I understand what you really want to do.  (It
certainly does what _I_ want it to do.  Other than to shut up after it
detects the first difference.)  DIFFERENCES has one fundamental
limitation for a task like this:

      HELP DIFFERENCES Parameters
[...]
The asterisk (*) and the percent sign (%) wildcard characters are not
allowed.
[...]

   While the HELP may not say so, it doesn't like "[...]", either:

alp $ diff [...]a.b [.x]
%DIFF-F-NOWILD, no wildcard permitted

   BACKUP /COMPARE _loves_ wildcards (as shown above).  You could write
a DCL script to do the recursive descent for DIFFERENCES, but it might
be a lot of work for no obvious reason.


   Also useful for comparisons with recursive descent in a directory
tree is GNU "diff":

      http://antinode.info/dec/sw/diffutils.html

which I also use from time to time for tasks like this.

   And GNU "diff -r", being very UNIXy, has no idea what a file version
number is, so about all it _can_ do easily is compare one highest
version against another highest version.