binary compatibility query

[Zaphod Beeblebrox]

 FreeBSD Hackers,
> > >
> > > I have a general question about the compatibility of FreeBSD binaries
> > > within major releases.  If I build a binary for a given release of
> > > FreeBSD can I make a reasonable guarantee that the binary will run on
> >
> > As a datapoint, I have been using cistron-radiusd for some time.
Recently, I got a new system to run it and compiled the port on it.  The
compiled port didn't work on amd64 (or my configuration didn't jive with the
new version of the daemon).

So I grabbed the i386 binary that was built likely around 4.6 to 4.8 FreeBSD
(I don't even remember --- it was so long ago). and dropped it on the amd64
7.0-RELEASE system.  The binary is dynamically linked (albeit not depending
on other packaged libraries) and I had the compat4, compat5 and compat6
ports installed on the new machine.  It runs (and is still running) just
fine.

That's pretty good for compatibility.