.rem or .soap and SAO

I never understood the difference when setting up Server Activated Objects.  Mike Woodring cleared it up for me:

If my memory serves me right, I think historically there was a point
during the pre-release cycles when the extensions had more meaning.
Something like this IIRC:

* .soap would imply the default use SoapFormatter unless otherwise
configured
* .bin would immply the default use BinaryFormatter unless otherwise
configured
* .rem was intended to only be used by the remoting infrastructure for
doing things like instantiating client activated types on remote
machines

But that was back in the day when the remoting config files used
#-delimited fields instead of the more readable xml format.  Then at
some point they just simplified things and demoted the extension's
importance to strictly routing - and relying solely on configuration
files to determine what you wanted to use.