> This hits my major long term use Scheme case: backup programs, where you
> must capture a great deal of information about all file objects.
>
> On the other hand, quite a bit more is needed for certain types, or
> should I say qualities, of backups, vs. a tar equivalent:

Good point! Things like rsync() et.al. This didn't occur to me at all.

Also, any procedure for symbolic links introduces a potential point of
incompatibility with Windows (which IIRC now has 1-3 different kinds of
symlinks, depending on how you count, none of which work as well as
Unix's one kind of symlink).