Miscellaneous questions

[David Shaw]

On Tue, Apr 15, 2008 at 08:40:17AM -0500, Robert J. Hansen wrote:
>> Why? Just because new (perhaps incompatible) features are added in
>> newer versions,... nobody has to use that newer versions, right?
>
> If you put GnuPG 3.0 available for download, everyone who's looking for the 
> latest release will grab it.  The people who are quite happy with 1.2, 1.4 
> or 2.0 won't.
>
> Now imagine that 3.0 breaks backwards compatibility.
>
> Anarchy ensues.  A lot of your users can't talk to each other.  Most of 
> them don't know why.  "I'm using GnuPG 3.0, I don't know why it can't talk 
> to PGP 5.0, I mean, GnuPG 2.0 could...!"
>
> Ensuring a migration path is so critically important in software 
> engineering.  Breaking backwards compatibility is seen as an extreme step.

It is frequently commented on, and not just in a tongue in cheek
manner, that it is a shame that the earlier versions of PGP weren't
broken.  If the old stuff had been broken, we would have no reason to
maintain compatibility with it.

David