[ih] early competition and networking

[John Levine]

It appears that Dave Crocker via Internet-history <dcrocker at bbiw.net> said:
>My understanding is that the design model then and now is a homogeneous 
>service, on top a variety of heterogeneous services. Hiding the 
>differences by providing a common service on top of them.  That the 
>common service was originally specified as one layer and evolved into 
>two does not change the meta-design approach.

Back in the day we moved a fair amount of mail via UUCP, a store and
forward dialup scheme quite different from SMTP. The format of the
mail messages was the same, and once we had the uucp mapping project
to figure out the routing, the addresses looked pretty much the same,
too, e.g. my address was johnl at ima.uucp. The sendmail mail program,
which is still widely used today, has a complex internal language to
describe how to route various addresses while keeping everything above
the same.

The ability to use the same higher level software and just futz with the
lower levels was and is quite powerful.

R's,
John