Don't really see why it would need to be active; a standard MIME
message/external-body with a pointer to the information (probably
along with a textual explanation and whatever else seems appropriate)
should suffice nicely.
>"Viewer" == Mosaic++, ...etc
>I want to get a response that is in such a form that an integrated
>intelligent viewer can give a homogeneous interface to the user.
A structured mail message certainly should be able to do that...
>I would expect that using e-mail would be difficult to smoothly
>integrate and probably a pain to administer. Rather, I would want a
>more unified and consistent exhange mechanism, so that, for example,
>only one TCP connection need be used.
This seems like a rather low level of problem to be worrying about;
what matters is that the server can somehow send a message to the user
which will cause the user's client to be directed to the new
information. Considering the server (presumably) has no way of
knowing where the user is, or whether he's running a client at all at
the moment, email seems very well suited to this task.
-- Marc VanHeyningen <http://www.cs.indiana.edu/hyplan/mvanheyn.html>